Downloads

Click on the underlined links below to download the files. All data files with a “.zip” or “.rar” at the end need to be unzipped after downloading (using WinZIP, WinRAR, 7-Zip, or a similar program).  Please regard Conditions of Use for all Rainfall Atlas products and refer to our How To Cite page for citation information.  

All mean map products use the 30 year base period 1978-2007.

*Added October, 2018: Rainfall Trend Maps from 1920-2012 & 1983-2012. See the Rainfall Trend Maps section below.

*Added December, 2015: Interactive map links for Month-Year Rainfall Maps from 1920-2012. See the Month-Year Maps section below.

*Added August, 2015: Month-Year Rainfall Maps from 1920-2012. See the Month-Year Maps section below.

*Added April, 2015: Raingage station data (through 2012). See the Tabular section below.

**The Moloka‘i maps have been updated! (07/2014) Using new information from stream gauges and additional vegetation data, we have a produced improved maps of mean rainfall for the island of Moloka‘i. All files below have been updated with these new maps.**

Map Images

Image files of the color zone rainfall maps as well as the isohyets have been created and are available for download as *.TIF files. The user has a choice of inches or millimeters, and each compressed *.zip file contains all 12 months plus the annual map. The color maps are available at a statewide extent as well as for each county, while the isohyets maps are only available for each island county (Maui Nui includes the islands of Maui, Moloka‘i, Lāna‘i and Kaho‘olawe).

 

Isohyets:

Isohyet Images

These images show the mean monthly rainfall as isohyets, or lines of equal rainfall. Both sets of isohyets (inches and mm) were created at appropriate intervals for their units, and therefore are not direct conversions of each other, though they are derived from the same data. The labels are included where they can fit, which means that not all isohyets are labeled, especially in steep gradient areas. Please see the interactive map or download the GIS or Google Earth layers for more information on isohyets labels.

 

Files for download:

CoverageInchesMillimeters
Hawai‘i HawaiiIsohyetTIFs_inches.zip HawaiiIsohyetTIFs_mm.zip
Kaua‘i KauaiIsohyetTIFs_inches.zip KauaiIsohyetTIFs_mm.zip
Maui Nui MauiNuiIsohyetTIFs_inches.zip MauiNuiIsohyetTIFs_mm.zip
O‘ahu OahuIsohyetTIFs_inches.zip OahuIsohyetTIFs_mm.zip

 

Color Maps:

Color Map Images

Unlike the interactive map which shows the rainfall as a continuous color ramp, these images display the rainfall in categories. The categories were set based on the natural breaks in the rainfall values for each extent, with the minimum and maximum values in the legend corresponding to the minimum and maximum values shown in the map extent. The categories were set independently for inches and millimeters, so the two sets will differ slightly.

 

 

Files for download:

CoverageInchesMillimeters
State StateMapTIFs_inches.zip StateMapTIFs_mm.zip
Hawai‘i HawaiiMapTIFs_inches.zip HawaiiMapTIFs_mm.zip
Kaua‘i KauaiMapTIFs_inches.zip KauaiMapTIFs_mm.zip
Maui Nui MauiNuiMapTIFs_inches.zip MauiNuiMapTIFs_mm.zip
O‘ahu OahuMapTIFs_inches.zip OahuMapTIFs_mm.zip

GIS Layers

GIS layers of the rainfall isohyets, rainfall grids, raingage stations, and uncertainty have been made available for download. Users can download the isohyets and stations as shapefiles, and the rainfall and uncertainty grids have been made available in ESRI and ASCII grid formats. These are available in either inches or millimeters, and each compressed *.zip file contains all 12 months plus the annual map. Rainfall isohyets and grids are available for the entire state or users can choose to download individual islands (Maui Nui includes the islands of Maui, Moloka‘i, Lāna‘i and Kaho‘olawe). Two station shapefiles are available (the same station information used in the interactive map), and the uncertainty grids are only available at the statewide extent. All files use geographic coordinates, WGS84 datum.

For more information about GIS, how to use GIS layers, or to obtain more Hawai‘i layers, please refer to the Hawai‘i State GIS page, http://www.state.hi.us/dbedt/gis/download.htm.  After downloading, users can upload layers to ArcGIS Online to make their own maps as an alternative to using a desktop GIS program, http://www.arcgis.com/home/.

 

Rainfall Grids:

Raster files are available at 250m resolution (0.00225 x 0.00225 cell size) for each island and for the state. These are available in inches or millimeters, and can be downloaded in ESRI grid format or ASCII grid format. These are the main output of this project, with the isohyets and other products being produced from these grids.

ESRI Grid Format:

CoverageInchesMillimeters
State StateRFGrids_inches.zip StateRFGrids_mm.zip
Hawai‘i HawaiiRFGrids_inches.zip HawaiiRFGrids_mm.zip
Kaua‘i KauaiRFGrids_inches.zip KauaiRFGrids_mm.zip
Maui Nui MauiNuiRFGrids_inches.zip MauiNuiRFGrids_mm.zip
O‘ahu OahuRFGrids_inches.zip OahuRFGrids_mm.zip
Maui MauiRFGrids_inches.zip MauiRFGrids_mm.zip
Lāna‘i LanaiRFGrids_inches.zip LanaiRFGrids_mm.zip
Moloka‘i MolokaiRFGrids_inches.zip MolokaiRFGrids_mm.zip

 

ASCII Grid Format:

CoverageInchesMillimeters
State StateASCIIGrids_inches.zip StateASCIIGrids_mm.zip
Hawai‘i HawaiiASCIIGrids_inches.zip HawaiiASCIIGrids_mm.zip
Kaua‘i KauaiASCIIGrids_inches.zip KauaiASCIIGrids_mm.zip
Maui Nui MauiNuiASCIIGrids_inches.zip MauiNuiASCIIGrids_mm.zip
O‘ahu OahuASCIIGrids_inches.zip OahuASCIIGrids_mm.zip
Maui MauiASCIIGrids_inches.zip MauiASCIIGrids_mm.zip
Lāna‘i LanaiASCIIGrids_inches.zip LanaiASCIIGrids_mm.zip
Moloka‘i MolokaiASCIIGrids_inches.zip MolokaiASCIIGrids_mm.zip

 

Rainfall Isohyets:

Rainfall isohyet files are available as polyline shapefiles for each island and for the state. These are available in inches or millimeters, and the "Contour" column in the attribute table contains the isohyet labels. Both sets of isohyets (inches and mm) were created at appropriate intervals for their units, and therefore are not direct conversions of each other, though they are derived from the same data.

 

CoverageInchesMillimeters
State StateIsohyetsSHP_inches.zip StateIsohyetsSHP_mm.zip
Hawai‘i HawaiiIsohyetsSHP_inches.zip HawaiiIsohyetsSHP_mm.zip
Kaua‘i KauaiIsohyetsSHP_inches.zip KauaiIsohyetsSHP_mm.zip
Maui Nui MauiNuiIsohyetsSHP_inches.zip MauiNuiIsohyetsSHP_mm.zip
O‘ahu OahuIsohyetsSHP_inches.zip OahuIsohyetsSHP_mm.zip
Maui MauiIsohyetsSHP_inches.zip MauiIsohyetsSHP_mm.zip
Lāna‘i LanaiIsohyetsSHP_inches.zip LanaiIsohyetsSHP_mm.zip
Moloka‘i MolokaiIsohyetsSHP_inches.zip MolokaiIsohyetsSHP_mm.zip

 

Raingage Stations:

Two point shapefiles containing station information are available for download. "RFAtlasStations" refers to the stations used to create the final rainfall atlas maps. "OtherStations" refers to all other stations that have operated in Hawai‘i, but for various reasons could not be included in the final analysis. The data available in the attribute table can also be downloaded as a *.csv or Microsoft Excel *.xslx file (see Tabular Downloads). 

 

CoverageShapefileMetadata
State RFAtlasStationsSHP.zip RFAtlasStations_Metadata
State OtherStationsSHP.zip OtherStations_Metadata

 

Uncertainty:

The uncertainty grids are available at 250m resolution (0.00225 x 0.00225 cell size) for the state. These are available in inches or millimeters, and can be downloaded in ESRI grid format or ASCII grid format. These layers contain the combined standard error from all input sources to the final maps - see Methods for more information.

 

ESRI Grid Format:

CoverageInchesMillimeters
State UncertaintyGrids_inches.zip UncertaintyGrids_mm.zip

 

ASCII Grid Format:

CoverageInchesMillimeters
State UncertaintyASCIIGrids_inches.zip UncertaintyASCIIGrids_mm.zip

Google Earth Files

The same files seen in the interactive map have also been converted into *.KML (*.KMZ) files which can be viewed in Google Earth. The stations and isohyets (lines of equal rainfall) will display their attribute information when an element is clicked on in Google Earth. The color rainfall maps do not contain the value information as they do on the interactive site, so the best way to view these in Google Earth is to set the transparency to overlay it onto the imagery. Maui Nui includes the islands of Maui, Moloka‘i, Lāna‘i and Kaho‘olawe.

 

Google Earth

 

Station Legend

 


The StationsKML.zip file contains two station files: "RFAtlas Stations" refers to the stations used to create the final rainfall atlas maps. "Other Stations" refers to all the other stations that have operated in Hawai‘i, but for various reasons could not be included in the final analysis. Click on a station for more information. The symbols are set automatically for these stations to be the same as on the interactive map:

 

 

The isohyet KMLs are available in inches or millimeters, with "Contour" referring to the isohyet label when you click on a line (labels will not be displayed unless you click on a line). Both sets of isohyets (inches and mm) were created at appropriate intervals for their units, and therefore are not direct conversions of each other, though they are derived from the same data.

 

CoverageInchesMillimeters
State IsohyetsKML_inches.zip IsohyetsKML_mm.zip

 

Color Map KMLs are available by island: (use transparency in Google Earth for best viewing, as no legend is available at this time for these layers):

 

Tabular

All station data available for download on our website are monthly totals.

For daily station data, Longman et al. 2018 have compiled and quality controlled the data from 1990-2014 - available for download here.


Added April, 2015: Raingage station data (through 2012):

There are two formats available:

Processed Original Data: data that have been screened for outliers and inhomogeneities, includes data values from all years available at the time of data collection (1837-2013)

Filled Data 1920-2012: data from 1920-2012 with missing values filled whenever possible (see methods)

A "Read_Me" tab has been included with each of these files to further explain the contents.

Excel 2007 Format
Processed Original Monthly Data 2012
Filled Monthly Dataset, 1920-2012

Note: We have not compiled rain gauge data beyond 2013 (what is available in the "2012" database above). If you need more current data, please contact the individual agencies that maintain the gages.

NCDC: http://www.ncdc.noaa.gov/cdo-web/

USGS: http://wdr.water.usgs.gov/allsearch.php (climatological sites)

RAWS: http://www.raws.dri.edu/wraws/hiF.html

SCAN: http://www.wcc.nrcs.usda.gov/scan/index.html

WRCC (should be the same stations from NCDC): http://www.wrcc.dri.edu/summary/Climsmhi.html

Hydronet: http://www.prh.noaa.gov/hnl/hydro/hydronet/hydronet-data.php

HaleNet: https://sites.google.com/a/hawaii.edu/ecohydrology_lab/current-research/halenet.

Hawai‘i State Climatologist - paper records of rain gauge data are stored in the State Climatologist's office: http://www.soest.hawaii.edu/MET/Hsco/

 

Original Rainfall Atlas Products (data end in 2007):

Raingage station data are available in *.csv (comma separated values) format as well as Microsoft Excel *.xlsx format.  The mean monthly data are available only for the stations used in the Rainfall Atlas (RFAtlas Stations).  The station information for all other stations is available as well (referred to as "Other Stations").  The monthly data are available in three different formats: Processed original data (data that have been screened for outliers and inhomogeneities), Filled Dataset (processed original data plus filled data from 1920-2007, used to create the Rainfall Atlas means), and Raw Original Monthly Data (the original data before removing inhomogeneities and other suspicious records).  All data files contain mm and inches.

An "About" tab has been included with each of these files to further explain the contents.  For details about the processing or gap filling, please read the final report, available for download below the tabular files.

 

Excel 2007 Format
CSV Format
Mean Rainfall Data - RFAtlas Stations Mean Rainfall Data - RFAtlas Stations
Station Information - Other Stations Station Information - Other Stations
Processed Original Monthly Data Processed Original Monthly Data
Filled Monthly Dataset, 1920-2007
Filled Monthly Dataset, 1920-2007
Raw Original Monthly Data Raw Original Monthly Data

Report

Rainfall Atlas of Hawai‘i 2011 - Final Report

 

Month-Year Maps 1920-2012

*NEW* as of August 7, 2015

Month-year rainfall maps for the State of Hawai‘i were created from January 1920 to December 2012 as a spin-off project from the original Rainfall Atlas of Hawai‘i. These maps can be downloaded below in ESRI grid format at 250 m resolution. The rainfall maps are available in either inches or millimeters, and each compressed *.rar file contains monthly and annual maps for every year (1920-2012). In addition to rainfall maps, we have also generated anomaly maps for each month-year, relative to the 1978-2007 (Rainfall Atlas) mean. The anomalies are calculated by dividing the monthly rainfall map by the monthly mean map (January 1920 Anomaly = January 1920 Rainfall / January Mean Rainfall). Units for anomaly maps are dimensionless. For complete methods, see citation below.

Please use the following citation for these maps:

Frazier, A. G., Giambelluca, T. W., Diaz, H. F. and Needham, H. L. (2016), Comparison of geostatistical approaches to spatially interpolate month-year rainfall for the Hawaiian Islands. Int. J. Climatol., 36(3), 1459-1470. doi: 10.1002/joc.4437

The link to the full article is here.

ESRI Grid Format:

Coverage (File Size)InchesMillimetersAnomaly
State (1.1 GB) State_RFGrids_1920_2012_in State_RFGrids_1920_2012_mm State_AnomGrids_1920_2012
Hawai‘i (650 MB) Hawaii_RFGrids_1920_2012_in Hawaii_RFGrids_1920_2012_mm Hawaii_AnomGrids_1920_2012
Kaua‘i (110 MB) Kauai_RFGrids_1920_2012_in Kauai_RFGrids_1920_2012_mm Kauai_AnomGrids_1920_2012
O‘ahu (120 MB) Oahu_RFGrids_1920_2012_in Oahu_RFGrids_1920_2012_mm Oahu_AnomGrids_1920_2012
Maui (155 MB) Maui_RFGrids_1920_2012_in Maui_RFGrids_1920_2012_mm Maui_AnomGrids_1920_2012
Lāna‘i (28 MB) Lanai_RFGrids_1920_2012_in Lanai_RFGrids_1920_2012_mm Lanai_AnomGrids_1920_2012
Moloka‘i (50 MB) Molokai_RFGrids_1920_2012_in Molokai_RFGrids_1920_2012_mm Molokai_AnomGrids_1920_2012

 

*NEW* as of December 11, 2015

Interactive Map Links (hosted by the PICCC Conservation Planning Atlas):

Annual Maps 1920-2012
Month-Year Maps 1920-1929
Month-Year Maps 1930-1939
Month-Year Maps 1940-1949
Month-Year Maps 1950-1959
Month-Year Maps 1960-1969
Month-Year Maps 1970-1979
Month-Year Maps 1980-1989
Month-Year Maps 1990-1999
Month-Year Maps 2000-2012

 

From the month-year maps we have generated Statewide and Island average monthly time series. Each index is the average of all map pixels for that month-year. These are available for download in Microsoft Excel (*.xlsx) and CSV (*.csv) formats. Each file contains the average rainfall values in millimeters and inches.

Average time series derived from month-year maps:

Excel 2007 Format
CSV Format
State - Monthly Rainfall Index State - Monthly Rainfall Index
Hawaii Island - Monthly Rainfall Index Hawaii Island - Monthly Rainfall Index
Kauai - Monthly Rainfall Index Kauai - Monthly Rainfall Index
Oahu - Monthly Rainfall Index Oahu - Monthly Rainfall Index
Maui - Monthly Rainfall Index Maui - Monthly Rainfall Index
Lanai - Monthly Rainfall Index Lanai - Monthly Rainfall Index
Molokai - Monthly Rainfall Index Molokai - Monthly Rainfall Index

Again, please use the following citation for these rainfall indices:

Frazier, A. G., Giambelluca, T. W., Diaz, H. F. and Needham, H. L. (2016), Comparison of geostatistical approaches to spatially interpolate month-year rainfall for the Hawaiian Islands. Int. J. Climatol., 36(3), 1459-1470. doi: 10.1002/joc.4437

Rainfall Trend Maps 1920-2012

*NEW* as of October 10, 2018

Month-year rainfall maps for the State of Hawai‘i (see data tab above) were used to calculate rainfall trends from 1920 to 2012, and for the most recent 30-year period available, 1983-2012. Wet season (November-April), Dry season (May-October), and Annual trends were calculated at each 250 m pixel across the state and mapped to produce spatially continuous trend maps. Statistically significant trends (p<0.05) are indicated with black hatching. Units are percent per decade (relative to the Rainfall Atlas 1978-2007 means). Trend maps can be downloaded as JPEG images below for each island. For complete methods, see citation below.

Please use the following citation for these rainfall trend maps:

Frazier, A. G., and Giambelluca, T. W. (2017), Spatial trend analysis of Hawaiian rainfall from 1920 to 2012. Int. J. Climatol., 37(5), 2522-2531. doi: 10.1002/joc.4862

The link to the full article is here.

 

JPEG Images Statewide:

Annual State Trends 1920-2012

Annual State Trends 1983-2012

 

Spatial Coverage & Season1920-2012 Trends1983-2012 Trends
State: Annual Trends State Annual Trends, 1920-2012 State Annual Trends, 1983-2012
State: Wet Season Trends State Wet Season Trends, 1920-2012 State Wet Season Trends, 1983-2012
State: Dry Season Trends State Dry Season Trends, 1920-2012 State Dry Season Trends, 1983-2012

 

JPEG Images Statewide (panels):

Annual State (panel) Trends 1920-2012

Annual State (panel) Trends 1983-2012

 

Spatial Coverage & Season1920-2012 Trends1983-2012 Trends
State (panels): Annual Trends State Annual Trends, 1920-2012 State Annual Trends, 1983-2012
State (panels): Wet Season Trends State Wet Season Trends, 1920-2012 State Wet Season Trends, 1983-2012
State (panels): Dry Season Trends State Dry Season Trends, 1920-2012 State Dry Season Trends, 1983-2012

 

JPEG Images by Island (Annual, Wet Season, Dry Season):

Maui Trends 1920-2012

Maui Trends 1983-2012

 

Spatial Coverage1920-2012 Trends1983-2012 Trends
Hawai‘i Island Hawai‘i Island Seasonal Rainfall Trends, 1920-2012 Hawai‘i Island Seasonal Rainfall Trends, 1983-2012
Kaua‘i Kaua‘i Seasonal Rainfall Trends, 1920-2012 Kaua‘i Island Seasonal Rainfall Trends, 1983-2012
O‘ahu O‘ahu Seasonal Rainfall Trends, 1920-2012 O‘ahu Island Seasonal Rainfall Trends, 1983-2012
Maui Maui Seasonal Rainfall Trends, 1920-2012 Maui Island Seasonal Rainfall Trends, 1983-2012
Lāna‘i & Moloka‘i Moloka‘i and Lāna‘i Seasonal Rainfall Trends, 1920-2012 Moloka‘i and Lāna‘i Seasonal Rainfall Trends, 1983-2012
Maui Nui (Maui, Moloka‘i, Lāna‘i, and Kaho‘olawe) Maui Nui Seasonal Rainfall Trends, 1920-2012 Maui Nui Island Seasonal Rainfall Trends, 1983-2012

 

Mean 1920–2012 trends for each island and season in percent per decade based on the 1978–2007 mean, and mm per decade:

Mean 1920–2012 trends for each island and season

 

Again, please use the following citation for these rainfall trend maps:

Frazier, A. G., and Giambelluca, T. W. (2017), Spatial trend analysis of Hawaiian rainfall from 1920 to 2012. Int. J. Climatol., 37(5), 2522-2531. doi: 10.1002/joc.4862

Conditions of Use

All maps, data, graphs, and narrative material available on this web site are subject to the following conditions.

Images. All color and isohyet rainfall map images presented here are available for reproduction and distribution. The map source must be included in any reproduction.

Gridded Map and Tabular Data. All gridded and tabular data and all other data presented here are available for reproduction and distribution for non-commercial use. The data source must be prominently stated whenever presenting these data in any form or any product derived in whole or part from these data.

Crediting the Source. Any reproduction or use of the images, maps, graphs, data, other information, or any product derived in whole or part from these data must credit the source in the following manner:

Giambelluca, T.W., Q. Chen, A.G. Frazier, J.P. Price, Y.-L. Chen, P.-S. Chu, J.K. Eischeid, and D.M. Delparte, 2013: Online Rainfall Atlas of Hawai‘i. Bull. Amer. Meteor. Soc. 94, 313-316, doi: 10.1175/BAMS-D-11-00228.1.

Sponsors of the 2011 Rainfall Atlas of Hawaiʻi. The 2011 Rainfall Atlas of Hawai‘i was developed under an agreement between the State of Hawaiʻi Commission on Water Resource Management and the U.S. Army Corps of Engineers, Honolulu District under Section 22 of the Water Resources Development Act of 1974.

No Warranty. We have made every effort to make all images, maps, graphs, data, and other information provided on this web site accurate and error-free. However, we do not guarantee the accuracy of any images, maps, graphs, data, or other information. All content is provided without warranty of any kind.