United States · 1991–2020

Best time to visit
Rancho San Diego.

May leads for comfortable weather in Rancho San Diego: typically 25.1°C by day, 13.3°C at night, with 8 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortMay

Typical high25.1°C

Typical low13.3°C

Rain in May8 mm

Comfort

May

May · April · June

93climate match

Beach

July

July · August · September

86climate match

Outdoors

March

March · April · December

88climate match

The weakest month is August, scoring 68 against May’s 93 — days average 31.8°C, 8° above 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

7021.2° / 5.9°

Feb

6921.1° / 7°

Mar

8122.3° / 9°

Apr

9124.2° / 10.5°

May

9325.1° / 13.3°

Jun

8827.6° / 15.2°

Jul

7430.5° / 17.5°

Aug

6831.8° / 18.2°

Sep

7231.3° / 16.9°

Oct

8427.9° / 13.2°

Nov

8724.4° / 8.4°

Dec

6920.7° / 5.6°

Monthly climate evidence for Rancho San Diego — daylight is calculated from latitude, everything else is measured, sea temperature from the nearest open water 22 km away
Month	Day	Night	Rain	Wet days	Sea	Daylight	Comfort	Coverage
January	21.2°C	5.9°C	59 mm	4.8	15.3°C	10 h 13	70	Strong coverage
February	21.1°C	7°C	67 mm	5.4	15.1°C	10 h 58	69	Strong coverage
March	22.3°C	9°C	45 mm	4.3	15.5°C	11 h 53	81	Strong coverage
April	24.2°C	10.5°C	19 mm	2.6	16.1°C	12 h 57	91	Strong coverage
May	25.1°C	13.3°C	8 mm	1.2	17.3°C	13 h 49	93	Strong coverage
June	27.6°C	15.2°C	2 mm	0.5	18.6°C	14 h 18	88	Strong coverage
July	30.5°C	17.5°C	5 mm	0.4	20.2°C	14 h 07	74	Strong coverage
August	31.8°C	18.2°C	1 mm	0.1	21.0°C	13 h 21	68	Strong coverage
September	31.3°C	16.9°C	2 mm	0.5	20.5°C	12 h 20	72	Good coverage
October	27.9°C	13.2°C	15 mm	1.3	19.3°C	11 h 19	84	Strong coverage
November	24.4°C	8.4°C	26 mm	2.8	17.5°C	10 h 26	87	Strong coverage
December	20.7°C	5.6°C	50 mm	4.4	16.0°C	10 h 00	69	Strong coverage

Records at EL CAJON, 1979–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	33.9°C15 Jan 2021	-3.3°C17 Jan 1987	70 mm22 Jan 2024	290 mm1993 · driest 0 mm in 2003	46
February	35.0°C22 Feb 2002	-2.2°C15 Feb 1990	64 mm21 Feb 1980	263 mm1998 · driest 0 mm in 2002	45
March	38.3°C20 Mar 2026	-1.1°C16 Mar 1988	54 mm5 Mar 1995	245 mm1983 · driest 0 mm in 2026	43
April	40.0°C6 Apr 1989	2.2°C10 Apr 1999	48 mm10 Apr 2020	109 mm2020 · driest 0 mm in 2017	45
May	40.0°C3 May 2004	6.1°C1 May 1999	23 mm7 May 2017	35 mm2017 · driest 0 mm in 1999	46
June	41.7°C20 Jun 2016	7.8°C5 Jun 1999	12 mm10 Jun 1990	23 mm1990 · driest 0 mm in 1988	43
July	45.0°C22 Jul 2006	10.0°C2 Jul 2004	48 mm31 Jul 2006	48 mm2006 · driest 0 mm in 2019	43
August	41.7°C13 Aug 1994	10.0°C6 Aug 2000	31 mm20 Aug 2023	48 mm2023 · driest 0 mm in 2013	43
September	45.6°C5 Sep 2020	9.4°C30 Sep 1982	19 mm25 Sep 1986	22 mm1986 · driest 0 mm in 1992	40
October	41.1°C10 Oct 1991	1.7°C23 Oct 2011	48 mm10 Oct 1986	133 mm2004 · driest 0 mm in 1984	41
November	37.2°C7 Nov 2008	-1.7°C21 Nov 1979	61 mm25 Nov 1985	183 mm1985 · driest 0 mm in 2017	45
December	33.9°C4 Dec 1979	-3.9°C25 Dec 1987	97 mm22 Dec 2010	199 mm2010 · driest 0 mm in 2000	42

Typical days per month at EL CAJON, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)
January	8	1	<1	2
February	6	1	<1	2
March	8	2	0	1
April	12	3	0	<1
May	14	4	0	<1
June	22	8	0	0
July	29	17	0	<1
August	28	20	0	0
September	27	18	0	0
October	20	9	0	<1
November	13	4	<1	1
December	6	<1	1	2

How often, not how much — every day in EL CAJON’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	55%	16%	7%	17%	18.9–23.2°C
February	56%	18%	8%	21%	18.6–23.8°C
March	63%	17%	6%	17%	19.4–25.1°C
April	79%	9%	2%	6%	22.1–26.4°C
May	88%	4%	<1%	<1%	22.3–27.5°C
June	98%	1%	<1%	<1%	25.6–29.8°C
July	99%	1%	<1%	<1%	28.8–32.7°C
August	99%	<1%	<1%	0%	29.8–33.3°C
September	98%	3%	<1%	<1%	29.2–33.1°C
October	93%	5%	1%	3%	25.2–29.7°C
November	79%	10%	4%	7%	21.9–26.2°C
December	56%	14%	5%	13%	18.6–23.2°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.

1980Each stripe is one year’s mean temperature against the 30-year average. Warmest: 2014. Coolest: 2023.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 5386053
NOAA station: USC00042706 · EL CAJON
Station distance: 6 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 24 usable years
Daylight: Calculated from latitude 32.75°, mid-month, sunrise to sunset including refraction. Not a station measurement.
Sea temperature: NOAA OISST v2.1 1991–2020 monthly climatology, nearest open water 22 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 EL CAJON is what differs

El Cajon→Santee→Lakeside→Winter Gardens→Bostonia→Jamul→

Or put two places side by side: Rancho San Diego vs El Cajon

Best time to visitRancho San Diego.

May

July

March

The whole year,without the guesswork.

Nearby, measured,and named.

Best time to visit
Rancho San Diego.

The whole year,
without the guesswork.

Nearby, measured,
and named.