United States · 1991–2020

Best time to visit
Windsor.

May leads for comfortable weather in Windsor: typically 24°C by day, 8.1°C at night, with 26 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortMay

Typical high24°C

Typical low8.1°C

Rain in May26 mm

Comfort

May

May · October · June

88climate match

Beach

August

August · July · September

72climate match

Outdoors

April

April · May · October

86climate match

The weakest month is December, scoring 20 against May’s 88 — days reach only 14.3°C, 10° below the 24°C the score treats as ideal, and nights drop to 2.7°C.

Month by month

The whole year,
without the guesswork.

The bars show the comfort score. Day and night temperatures come from daily observed highs and lows; rain is the historical monthly estimate.

Jan

2514.6° / 2.9°

Feb

3316.5° / 3.9°

Mar

4818.4° / 5.1°

Apr

6820.6° / 6.2°

May

8824° / 8.1°

Jun

7927.7° / 10.1°

Jul

7828.6° / 11°

Aug

7728.8° / 11.1°

Sep

7628.6° / 9.9°

Oct

8125° / 7.5°

Nov

5318.5° / 4.6°

Dec

2014.3° / 2.7°

Monthly climate evidence for Windsor — daylight is calculated from latitude, everything else is measured, sea temperature from the nearest open water 33 km away
Month	Day	Night	Rain	Wet days	Sea	Daylight	Comfort	Coverage
January	14.6°C	2.9°C	145 mm	9.8	11.5°C	9 h 45	25	Good coverage
February	16.5°C	3.9°C	155 mm	8.9	11.7°C	10 h 42	33	Good coverage
March	18.4°C	5.1°C	107 mm	9	11.5°C	11 h 50	48	Good coverage
April	20.6°C	6.2°C	53 mm	5.5	10.7°C	13 h 09	68	Good coverage
May	24°C	8.1°C	26 mm	2.6	10.6°C	14 h 15	88	Good coverage
June	27.7°C	10.1°C	6 mm	0.9	10.7°C	14 h 50	79	Good coverage
July	28.6°C	11°C	0 mm	0.1	11.5°C	14 h 36	78	Good coverage
August	28.8°C	11.1°C	0 mm	0.1	12.4°C	13 h 40	77	Good coverage
September	28.6°C	9.9°C	4 mm	0.9	12.9°C	12 h 23	76	Good coverage
October	25°C	7.5°C	43 mm	3.5	12.8°C	11 h 07	81	Good coverage
November	18.5°C	4.6°C	88 mm	6.7	12.4°C	10 h 01	53	Good coverage
December	14.3°C	2.7°C	174 mm	10.1	11.8°C	9 h 29	20	Good coverage

Records at SANTA ROSA SONOMA CO AP, 1998–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	27.8°C12 Jan 2009	-6.7°C15 Jan 2007	91 mm8 Jan 2017	482 mm2017 · driest 3 mm in 2015	28
February	29.4°C15 Feb 2016	-3.8°C20 Feb 2018	118 mm26 Feb 2019	431 mm2019 · driest 0 mm in 2020	28
March	32.8°C20 Mar 2026	-2.2°C10 Mar 2009	93 mm9 Mar 2023	326 mm2023 · driest 3 mm in 2015	28
April	34.4°C26 Apr 2004	-0.6°C1 Apr 1999	70 mm6 Apr 2018	148 mm2006 · driest 0 mm in 2008	28
May	38.9°C15 May 2008	0.0°C10 May 2022	54 mm18 May 2005	128 mm2005 · driest 0 mm in 2021	28
June	42.2°C14 Jun 2000	3.9°C7 Jun 1999	29 mm25 Jun 2013	40 mm2011 · driest 0 mm in 2019	29
July	42.2°C22 Jul 2006	5.0°C6 Jul 2009	2 mm25 Jul 2003	3 mm2007 · driest 0 mm in 2009	29
August	41.7°C24 Aug 2010	5.6°C30 Aug 2010	2 mm24 Aug 2024	2 mm2020 · driest 0 mm in 2014	28
September	45.6°C6 Sep 2022	2.8°C30 Sep 2019	22 mm18 Sep 2022	25 mm2022 · driest 0 mm in 2024	28
October	41.1°C1 Oct 2024	-2.7°C30 Oct 2019	155 mm24 Oct 2021	274 mm2021 · driest 0 mm in 2020	28
November	31.7°C14 Nov 2008	-4.9°C29 Nov 2015	176 mm20 Nov 2024	393 mm2024 · driest 20 mm in 2007	28
December	25.6°C19 Dec 1999	-7.1°C9 Dec 2013	118 mm11 Dec 2014	456 mm2005 · driest 2 mm in 2017	28

Typical days per month at SANTA ROSA SONOMA CO AP, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)
January	<1	0	9	4
February	1	0	5	5
March	3	<1	1	4
April	6	1	<1	2
May	13	4	0	<1
June	21	10	0	<1
July	26	11	0	0
August	26	12	0	0
September	23	11	0	<1
October	16	6	<1	1
November	3	<1	4	3
December	<1	0	11	5

How often, not how much — every day in SANTA ROSA SONOMA CO AP’s record sorted by what it was actually like, rather than averaged
Month	Warm & dry days	Wet days	Washouts	Week with 3+ wet days	Daytime mean has ranged
January	9%	30%	14%	37%	12.9–16.7°C
February	23%	31%	17%	45%	14.6–19.6°C
March	37%	29%	11%	32%	15.8–21.5°C
April	54%	17%	6%	18%	18.8–22.3°C
May	81%	8%	2%	6%	21.7–26.6°C
June	95%	3%	<1%	<1%	25.1–29.1°C
July	99%	<1%	0%	0%	27.2–30.9°C
August	99%	<1%	0%	0%	27.2–30.9°C
September	95%	4%	<1%	2%	26.9–30.4°C
October	79%	12%	4%	12%	22.5–28.2°C
November	34%	22%	10%	29%	16.8–20.5°C
December	4%	34%	18%	47%	12.8–16.2°C

A warm and dry day reaches 20°C with under 1 mm of rain; a wet day gets 1 mm or more; a washout gets 10 mm or more. The week column is the share of seven-day stretches in that month, across the station’s whole daily record, that contained three or more wet days — the odds a week-long trip is rained on repeatedly, counted rather than modelled. The last column is the 10th to 90th percentile of that month’s daytime average across individual years: a narrow band means the average is what you will get, a wide one means the average is a midpoint between years that felt quite different.

1999Each stripe is one year’s mean temperature against the 27-year average. Warmest: 2014. Coolest: 1999.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 5410004
NOAA station: USW00023213 · SANTA ROSA SONOMA CO AP
Station distance: 4.9 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 22 usable years
Daylight: Calculated from latitude 38.55°, mid-month, sunrise to sunset including refraction. Not a station measurement.
Sea temperature: NOAA OISST v2.1 1991–2020 monthly climatology, nearest open water 33 km from the place centre. A sheltered bay can run warmer than the open sea it is measured from.
Important limit: Historical climate is not a forecast. Nearby stations can miss mountains, coasts, and local microclimates.

These places read the same station, so their numbers are identical — distance from SANTA ROSA SONOMA CO AP is what differs

Larkfield-Wikiup→Fulton→East Windsor→Forest Hills→Hacienda→Hollydale→

Or put two places side by side: Windsor vs Larkfield-Wikiup

Best time to visitWindsor.

May

August

April

The whole year,without the guesswork.

Nearby, measured,and named.

Best time to visit
Windsor.

The whole year,
without the guesswork.

Nearby, measured,
and named.