United States · 1991–2020

Best time to visit
Vacaville.

May leads for comfortable weather in Vacaville: typically 26.7°C by day, 11°C at night, with 19 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortMay

Typical high26.7°C

Typical low11°C

Rain in May19 mm

Comfort

May

May · October · April

84climate match

Beach

June

June · September · August

72climate match

Outdoors

April

April · November · March

89climate match

The weakest month is December, scoring 30 against May’s 84 — days reach only 14.3°C, 10° below the 24°C the score treats as ideal, and nights drop to 3.3°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

3214.2° / 3.3°

Feb

4216.7° / 4.7°

Mar

6019.6° / 6.6°

Apr

8122.3° / 8.1°

May

8426.7° / 11°

Jun

7331.7° / 14.1°

Jul

6434.7° / 15.4°

Aug

6734.1° / 14.9°

Sep

7132° / 13.5°

Oct

8326.3° / 9.9°

Nov

6119° / 5.7°

Dec

3014.3° / 3.3°

Monthly climate evidence for Vacaville — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	14.2°C	3.3°C	110 mm	7.9	9 h 46	32	Good coverage
February	16.7°C	4.7°C	117 mm	7.5	10 h 42	42	Good coverage
March	19.6°C	6.6°C	82 mm	7.1	11 h 50	60	Good coverage
April	22.3°C	8.1°C	34 mm	3.6	13 h 08	81	Good coverage
May	26.7°C	11°C	19 mm	2.3	14 h 14	84	Good coverage
June	31.7°C	14.1°C	3 mm	0.7	14 h 49	73	Good coverage
July	34.7°C	15.4°C	0 mm	0.1	14 h 35	64	Good coverage
August	34.1°C	14.9°C	0 mm	0.1	13 h 39	67	Good coverage
September	32°C	13.5°C	2 mm	0.5	12 h 23	71	Good coverage
October	26.3°C	9.9°C	27 mm	2.6	11 h 08	83	Good coverage
November	19°C	5.7°C	57 mm	5.3	10 h 02	61	Good coverage
December	14.3°C	3.3°C	122 mm	8.4	9 h 30	30	Good coverage

Records at VACAVILLE/NUT TREE AP ASOS, 1998–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	25.6°C12 Jan 2009	-7.7°C17 Jan 2012	86 mm10 Jan 2017	424 mm2017 · driest 0 mm in 2015	28
February	29.4°C15 Feb 2016	-4.3°C24 Feb 2018	103 mm26 Feb 2019	325 mm2017 · driest 0 mm in 2020	28
March	32.2°C20 Mar 2026	-1.7°C8 Mar 2002	55 mm5 Mar 2016	258 mm2023 · driest 1 mm in 2020	28
April	36.1°C21 Apr 2009	-0.5°C6 Apr 2024	36 mm6 Apr 2017	103 mm2006 · driest 0 mm in 2020	29
May	41.1°C31 May 2001	1.1°C11 May 2022	44 mm28 May 1998	89 mm1998 · driest 0 mm in 2001	29
June	44.4°C28 Jun 2009	6.1°C8 Jun 1999	18 mm28 Jun 2011	39 mm2011 · driest 0 mm in 2018	29
July	46.1°C10 Jul 2021	9.4°C12 Jul 2001	2 mm18 Jul 2007	2 mm2007 · driest 0 mm in 2026	29
August	43.9°C15 Aug 2020	8.9°C27 Aug 2012	5 mm21 Aug 2003	10 mm2003 · driest 0 mm in 2010	27
September	46.1°C5 Sep 2022	5.0°C29 Sep 2019	11 mm18 Sep 2022	20 mm2022 · driest 0 mm in 2017	28
October	40.0°C2 Oct 2024	0.6°C31 Oct 2019	107 mm13 Oct 2009	114 mm2009 · driest 0 mm in 2019	28
November	31.7°C3 Nov 2018	-3.9°C29 Nov 2015	80 mm7 Nov 2002	132 mm2001 · driest 7 mm in 2021	28
December	24.4°C20 Dec 1999	-8.3°C23 Dec 1998	114 mm13 Dec 2002	389 mm2005 · driest 1 mm in 2017	28

Typical days per month at VACAVILLE/NUT TREE AP ASOS, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)
January	<1	0	7	3
February	<1	0	3	4
March	5	<1	<1	3
April	9	2	<1	1
May	20	9	0	<1
June	27	20	0	<1
July	30	27	0	0
August	31	27	0	0
September	28	21	0	0
October	20	7	0	<1
November	3	<1	2	2
December	0	0	8	4

How often, not how much — every day in VACAVILLE/NUT TREE AP ASOS’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%	25%	11%	29%	12.0–16.8°C
February	24%	26%	13%	35%	14.6–20.4°C
March	45%	23%	9%	26%	16.5–23.2°C
April	69%	12%	4%	10%	20.0–24.6°C
May	90%	7%	2%	4%	24.2–29.4°C
June	97%	2%	<1%	<1%	29.4–34.0°C
July	100%	<1%	0%	0%	32.6–37.1°C
August	100%	<1%	0%	0%	32.7–35.8°C
September	98%	2%	<1%	<1%	30.0–33.6°C
October	87%	7%	2%	8%	23.6–29.3°C
November	37%	17%	7%	19%	16.5–20.9°C
December	4%	28%	13%	38%	12.5–16.4°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: 2015. Coolest: 2011.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 5405228
NOAA station: USW00093241 · VACAVILLE/NUT TREE AP ASOS
Station distance: 3.4 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 22 usable years
Daylight: Calculated from latitude 38.36°, mid-month, sunrise to sunset including refraction. Not a station measurement.
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 VACAVILLE/NUT TREE AP ASOS is what differs

Elmira→Binghamton→Bunker→Cannon→Cordero Junction→Creed→

Or put two places side by side: Vacaville vs Elmira

Best time to visitVacaville.

May

June

April

The whole year,without the guesswork.

Nearby, measured,and named.

Best time to visit
Vacaville.

The whole year,
without the guesswork.

Nearby, measured,
and named.