Santa Rosa, CA weather in May
May in Santa Rosa: mild and mostly dry. Highs 75°F, lows 46°F, about 4 days with rain. A great month for outdoor plans.
- Normal high
- 75°F
- Normal low
- 46°F
- Wet days
- 4
- 1.4 in total
- Muggy days
- 0
- dew point 65°F+
How May changes from start to finish
| May 1 | May 31 | |
|---|---|---|
| Normal high | 73°F | 78°F |
| Normal low | 44°F | 47°F |
| Chance of a wet day | 16% | 10% |
| Sunrise / sunset | 6:13 am / 8:02 pm | 5:49 am / 8:28 pm |
| Daylight | 13.8 h | 14.7 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Pacific Time).
A typical May day
- 6 am54°Fdew point 48°F
- 9 am65°Fdew point 48°F
- Noon74°Fdew point 48°F
- 3 pm76°Fdew point 49°F
- 6 pm69°Fdew point 49°F
- 9 pm59°Fdew point 49°F
NOAA hourly normals (local standard time) from Travis AFB (44 mi away); average wind 15 mph; clear or few clouds in 69% of daytime hours, mostly cloudy or overcast in 23%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F19 of 31
- Hot dayshigh 90°F or more2 of 31
- Muggy daysdaily mean dew point 65°F or more0 of 31
- Wet daysat least 0.01 in of rain or melted snow4 of 31
- Notable rainat least 0.10 in2 of 31
- Freezing nightslow 32°F or below0 of 31
Average days per May, counted from daily records for each year 1991-2020.
Rain in May
Normal precipitation is 1.4 in; a dry May brings about 0.06 in and a wet one about 2.3 in (25th and 75th percentiles). About 1 day brings half an inch or more.
How May varies from year to year
- Warmest May, 1991-20202014: average high 83°F
- Coolest May1998: average high 67°F
- Wettest May2005: 5.5 in
- Driest May1992: no measurable precipitation
- Highest reading101°F (May 16, 2008)
- Lowest reading30°F (May 22, 2010)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
May compared with April and June
| April | May | June | |
|---|---|---|---|
| Normal high | 70°F | 75°F | 81°F |
| Normal low | 42°F | 46°F | 48°F |
| Wet days | 7 | 4 | 2 |
| Comfortable days | 20 | 19 | 12 |
| Daylight | 13.2 h | 14.3 h | 14.8 h |
Highs change by +5°F from April and +6°F into June.
Nearby alternatives in May
- Warmer: Sacramento, CA67 mi · high 81°F · 4 wet days
- Cooler: San Francisco, CA49 mi · high 64°F · 4 wet days
How Santa Rosa ranks in May
- Normal high190th warmest of 378 cities; 34th of 60 in California
- Wet days73rd driest of 378
- Comfortable days26th most of 339
What to pack for Santa Rosa in May
- Layers – afternoons near 75°F but nights near 46°F
- Sunglasses and sunscreen – about 14.3 hours of daylight and highs near 75°F
Heating and cooling
May has 160 heating degree days and 16 cooling degree days (base 65°F), 5% of the year's total heating and cooling demand.
Questions
How hot is Santa Rosa in May?
The normal high is 75°F and the normal low is 46°F. From 1991 to 2020 the hottest May reading was 101°F (May 16, 2008).
Does it rain a lot in Santa Rosa in May?
About 4 days in May have at least 0.01 in of precipitation, and the normal total is 1.4 in. The wettest May in 1991-2020 was in 2005 (5.5 in); the driest was in 1992, with no measurable precipitation.
Is May a good time to visit Santa Rosa?
May ranks 1st of 12 months on our comfort score for Santa Rosa (80 out of 100). It has about 19 comfortable days and about 2 days at 90°F or hotter. The best months are April and May.
Where the numbers come from
- Temperature and rain: Graton (USC00043578), 8.2 mi W of the city center, 200 ft . NOAA normals and daily records, 1991-2020.
- Snowfall, snow depth and frost dates: Santa Rosa (USC00047965), 1.1 mi N of the city center, 166 ft . NOAA normals and daily records, 1991-2020.
- Humidity and wind by hour and cloud cover: Travis AFB (USW00023202), 44 mi ESE of the city center, 59 ft (106 ft lower than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Sonoma County Airport (724957-23213), 6.8 mi NW of the city center, 119 ft . Hourly observations, 1991-2020.