San Rafael Weather in May

NASA POWER reanalysis for the half-degree grid cell around San Rafael, 1991-2020; a grid cell is an area average and can differ from a thermometer in town by several degrees

Average highs run from 34°C on May 1 to 34°C on May 31, and lows from 26°C to 27°C. Normal precipitation for the month is 74 mm over about 12 wet days.

May day by day

The normal high and low for each date, in °C.

Normal low
Normal high
Reanalysis extreme high
Reanalysis extreme low

May at a glance

Average high: 34°C
Average low: 27°C
Precipitation: 74 mm
Reanalysis high: 39°CMay 16, 2020
Reanalysis low: 24°CMay 20, 2006
Daylight: 12 h 32 min to 12 h 43 min
Cloud cover: 58%
Humidity: 70%
Dew point: 23°C
Wind: 21.2 km/h

Every day of the month

A wet day has at least 1 mm of precipitation in the reanalysis.

Date	Normal high	Normal low	Reanalysis high	Reanalysis low	Chance wet
May 1	34°C	26°C	37°C 2015	25°C 2009	34%
May 2	34°C	26°C	37°C 2019	26°C 2009	34%
May 3	34°C	26°C	37°C 2015	25°C 2000	34%
May 4	34°C	26°C	37°C 2015	25°C 2009	34%
May 5	34°C	26°C	37°C 2015	25°C 2009	34%
May 6	34°C	26°C	37°C 2015	25°C 2009	34%
May 7	34°C	26°C	37°C 2015	25°C 2006	34%
May 8	34°C	27°C	37°C 2008	25°C 1996	35%
May 9	34°C	27°C	39°C 2020	25°C 2006	35%
May 10	34°C	27°C	38°C 2020	26°C 2014	35%
May 11	34°C	27°C	37°C 2020	25°C 1999	35%
May 12	34°C	27°C	37°C 2000	25°C 1999	35%
May 13	34°C	27°C	37°C 2008	25°C 1999	36%
May 14	34°C	27°C	38°C 2016	25°C 2011	35%
May 15	34°C	27°C	38°C 2016	25°C 2011	35%
May 16	34°C	27°C	39°C 2020	26°C 2009	35%
May 17	34°C	27°C	38°C 2020	25°C 1995	35%
May 18	34°C	27°C	37°C 2020	25°C 2011	36%
May 19	34°C	27°C	38°C 2020	25°C 2011	36%
May 20	34°C	27°C	37°C 2016	24°C 2006	37%
May 21	34°C	27°C	37°C 2020	25°C 2006	39%
May 22	34°C	27°C	37°C 2016	25°C 2006	39%
May 23	34°C	27°C	37°C 2020	25°C 2001	40%
May 24	34°C	27°C	39°C 2020	25°C 2006	40%
May 25	34°C	27°C	37°C 2017	25°C 2006	41%
May 26	34°C	27°C	38°C 2020	25°C 2002	41%
May 27	34°C	27°C	36°C 2018	24°C 2002	40%
May 28	34°C	27°C	37°C 2012	25°C 1995	40%
May 29	34°C	27°C	36°C 2009	26°C 2002	38%
May 30	34°C	27°C	37°C 2003	25°C 2001	36%
May 31	34°C	27°C	36°C 2003	25°C 1995	36%

Chance of rain

Chance of a wet day

Sunrise and sunset

Times for 2026, local time (GMT-4).

May 1: sunrise 6:28 AM, sunset 7:00 PM
May 31: sunrise 6:23 AM, sunset 7:06 PM

Every day of May: sun and moon

Other months

Sources

Cloud, humidity, wind and sunshine, and temperature and precipitation: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.