United States · 1991–2020

Best time to visit
Sunnyvale.

July leads for comfortable weather in Sunnyvale: typically 25.1°C by day, 15°C at night, with 0 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortJuly

Typical high25.1°C

Typical low15°C

Rain in July0 mm

Comfort

July

July · August · June

96climate match

Beach

July

July · August · September

72climate match

Outdoors

April

April · May · November

97climate match

The weakest month is December, scoring 46 against July’s 96 — days reach only 15.1°C, 9° below the 24°C the score treats as ideal.

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

4715.2° / 5.7°

Feb

5116.6° / 7.1°

Mar

6418.5° / 8.4°

Apr

7620.2° / 9.6°

May

8822.2° / 11.6°

Jun

9524.7° / 13.5°

Jul

9625.1° / 15°

Aug

9625.1° / 15.2°

Sep

9425.5° / 14.3°

Oct

9323.4° / 12°

Nov

6818.6° / 8.2°

Dec

4615.1° / 5.8°

Monthly climate evidence for Sunnyvale — daylight is calculated from latitude, everything else is measured, sea temperature from the nearest open water 30 km away
Month	Day	Night	Rain	Wet days	Sea	Daylight	Comfort	Coverage
January	15.2°C	5.7°C	58 mm	7.1	12.2°C	9 h 51	47	Strong coverage
February	16.6°C	7.1°C	72 mm	8.6	12.3°C	10 h 45	51	Strong coverage
March	18.5°C	8.4°C	50 mm	7.7	12.3°C	11 h 51	64	Strong coverage
April	20.2°C	9.6°C	24 mm	4.3	12.0°C	13 h 06	76	Strong coverage
May	22.2°C	11.6°C	8 mm	1.5	12.2°C	14 h 09	88	Strong coverage
June	24.7°C	13.5°C	3 mm	0.6	12.9°C	14 h 43	95	Strong coverage
July	25.1°C	15°C	0 mm	0	14.1°C	14 h 30	96	Good coverage
August	25.1°C	15.2°C	0 mm	0	14.9°C	13 h 36	96	Strong coverage
September	25.5°C	14.3°C	2 mm	0.5	14.9°C	12 h 23	94	Good coverage
October	23.4°C	12°C	16 mm	2.3	14.2°C	11 h 10	93	Good coverage
November	18.6°C	8.2°C	32 mm	4.9	13.4°C	10 h 07	68	Good coverage
December	15.1°C	5.8°C	63 mm	7.4	12.5°C	9 h 36	46	Good coverage

What has changed

Sunnyvale runs +1.1°C
on the 1961–1990 baseline.

Each bar compares the 2011–2025 daytime average for that month against the same month in 1961–1990, measured at the same station. Months where the older record is too thin to compare are left blank.

Jan

+1.4

Feb

+0.7

Mar

+1.3

Apr

+1.1

May

+0.6

Jun

+1.2

Jul

+1.0

Aug

+0.8

Sep

+1.3

Oct

+1.4

Nov

+0.8

Dec

+1.0

July daytime highs, 2011–2025. Last recorded: 22.3°C.

Records at MOFFETT FED AIRFIELD, 1945–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	24.4°C23 Jan 1948	-6.1°C5 Jan 1949	69 mm4 Jan 1982	173 mm1978 · driest 0 mm in 2015	72
February	27.8°C26 Feb 1986	-3.3°C1 Feb 1950	68 mm14 Feb 1986	184 mm1986 · driest 3 mm in 1953	72
March	30.0°C20 Mar 2026	-1.1°C3 Mar 1951	38 mm2 Mar 1983	162 mm1983 · driest 2 mm in 1988	73
April	35.0°C9 Apr 1989	0.0°C4 Apr 1945	30 mm2 Apr 1958	101 mm1967 · driest 0 mm in 1946	73
May	39.4°C12 May 1976	3.3°C4 May 1952	25 mm27 May 1990	44 mm1977 · driest 0 mm in 2014	73
June	41.1°C14 Jun 2000	6.1°C1 Jun 1955	17 mm4 Jun 2011	31 mm2011 · driest 0 mm in 1948	74
July	39.4°C31 Jul 1993	7.2°C5 Jul 1955	10 mm2 Jul 1980	12 mm1980 · driest 0 mm in 2006	74
August	38.3°C1 Aug 1993	8.3°C30 Aug 1955	14 mm18 Aug 1975	16 mm1976 · driest 0 mm in 1959	73
September	41.1°C1 Sep 2017	5.0°C12 Sep 1946	50 mm18 Sep 1959	50 mm1959 · driest 0 mm in 2012	72
October	37.8°C5 Oct 1987	0.6°C20 Oct 1949	64 mm13 Oct 1962	90 mm1962 · driest 0 mm in 2018	71
November	30.6°C1 Nov 1967	-1.7°C24 Nov 1947	71 mm28 Nov 1970	142 mm1972 · driest 0 mm in 1956	72
December	25.6°C5 Dec 2003	-5.0°C23 Dec 1990	85 mm11 Dec 2014	243 mm1955 · driest 1 mm in 1989	72

Typical days per month at MOFFETT FED AIRFIELD, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)
January	0	0	1	2
February	<1	0	<1	2
March	2	0	0	1
April	4	<1	0	<1
May	6	2	0	<1
June	12	3	0	<1
July	15	2	0	0
August	15	3	0	0
September	14	5	0	<1
October	10	2	0	<1
November	1	0	<1	<1
December	0	0	<1	2

How often, not how much — every day in MOFFETT FED AIRFIELD’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	5%	23%	7%	29%	12.8–16.7°C
February	13%	27%	7%	35%	14.4–18.2°C
March	23%	25%	5%	28%	15.6–19.8°C
April	41%	14%	2%	13%	17.2–22.0°C
May	62%	5%	<1%	3%	19.4–23.8°C
June	86%	2%	<1%	0%	21.1–25.7°C
July	94%	<1%	0%	0%	22.2–25.9°C
August	95%	<1%	0%	<1%	22.6–25.8°C
September	92%	2%	<1%	<1%	22.8–26.9°C
October	72%	7%	2%	5%	20.7–24.5°C
November	28%	18%	4%	20%	16.5–19.9°C
December	3%	23%	6%	26%	12.8–16.3°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.

1946Each stripe is one year’s mean temperature against the 68-year average. Warmest: 2014. Coolest: 1955.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 5400075
NOAA station: USW00023244 · MOFFETT FED AIRFIELD
Station distance: 4.2 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 24 usable years
Daylight: Calculated from latitude 37.37°, mid-month, sunrise to sunset including refraction. Not a station measurement.
Sea temperature: NOAA OISST v2.1 1991–2020 monthly climatology, nearest open water 30 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 MOFFETT FED AIRFIELD is what differs

Mountain View→Cupertino→Los Altos→Loyola→Aloha Mobile Village→Alviso→

Or put two places side by side: Sunnyvale vs Mountain View

Best time to visitSunnyvale.

July

July

April

The whole year,without the guesswork.

Sunnyvale runs +1.1°Con the 1961–1990 baseline.

Nearby, measured,and named.

Best time to visit
Sunnyvale.

The whole year,
without the guesswork.

Sunnyvale runs +1.1°C
on the 1961–1990 baseline.

Nearby, measured,
and named.