Oceanside climate

Name: Oceanside
Address: US

Oceanside is warmest in August, with average highs of 26 °C, and coldest in January, when nights average 8.6 °C. February is the wettest month (91 mm) and August the driest (1.1 mm). Figures are 1991–2020 climate normals.

Across a full year Oceanside averages 372 mm of rain and 62 days above 25 °C.

United States · 20 m elevation · population 175,691 · 1991–2020 normals

Temperature below 0 °C to above 30 °C Rain band height is that month’s share of the wettest month

Warmest month August 26 °C
Coldest month January 8.6 °C
Driest month August 1 mm
Wettest month February 91 mm
Least cloud August 27 % cloud
Hottest on record October 37 °C
Coldest on record January 1.5 °C
Warmest sea August 21 °C

What to expectOceanside through the year

Oceanside has a clear annual cycle: average daily highs run from 17 °C in January to 26 °C in August, a swing of 9.4 °C in mean temperature across the year.

Counted across a normal year, 62 days a year reach 25 °C, 4 of them reach 30 °C. The warmest reading in the 1991–2020 record is 37 °C, in October.

Rain is strongly seasonal. February averages 91 mm against 1 mm in August — 84 times as much. Planning around the dry months matters more here than planning around temperature.

The sea off Oceanside is warmest in August at 21 °C and coldest in January at 15 °C. Sea temperature lags the air by a month or two, which is why late summer swims warmer than early summer at the same air temperature.

Month by month

Month	Avg high	Rainfall	Cloud
January	17.2 °C	73 mm	47 %
February	17.0 °C	91 mm	50 %
March	17.6 °C	59 mm	51 %
April	18.8 °C	28 mm	46 %
May	20.0 °C	13 mm	49 %
June	22.0 °C	3 mm	38 %
July	24.5 °C	2 mm	33 %
August	25.6 °C	1 mm	27 %
September	25.2 °C	4 mm	28 %
October	22.9 °C	18 mm	36 %
November	20.0 °C	26 mm	38 %
December	17.1 °C	56 mm	44 %

Temperature month by month

Month	Avg high	Avg low	Mean	Record high	Record low	Days above 25 °C	Days above 30 °C
January	17.2 °C	8.6 °C	12.5 °C	26.8 °C	1.5 °C	0	0
February	17.0 °C	9.1 °C	12.8 °C	26.9 °C	2.9 °C	0	0
March	17.6 °C	10.5 °C	13.8 °C	29.4 °C	3.7 °C	1	0
April	18.8 °C	11.9 °C	15.1 °C	30.7 °C	3.7 °C	1	0
May	20.0 °C	13.9 °C	16.6 °C	33.0 °C	8.7 °C	2	0
June	22.0 °C	15.8 °C	18.5 °C	34.3 °C	10.9 °C	3	0
July	24.5 °C	18.2 °C	20.9 °C	33.4 °C	14.0 °C	12	0
August	25.6 °C	19.2 °C	21.9 °C	32.7 °C	14.4 °C	18	1
September	25.2 °C	18.5 °C	21.4 °C	33.8 °C	12.8 °C	14	2
October	22.9 °C	15.7 °C	19.0 °C	36.9 °C	8.4 °C	8	1
November	20.0 °C	11.9 °C	15.7 °C	30.6 °C	3.8 °C	2	0
December	17.1 °C	8.8 °C	12.6 °C	26.0 °C	1.6 °C	0	0

Rain, sun and wind month by month

Month	Rainfall	Wet days	Daylight	Cloud cover	Humidity	Wind	Sea temp
January	73 mm	6	10 h/day	47 %	77 %	13 km/h	15.2 °C
February	91 mm	7	11 h/day	50 %	78 %	14 km/h	15.2 °C
March	59 mm	6	12 h/day	51 %	79 %	14 km/h	15.5 °C
April	28 mm	4	13 h/day	46 %	77 %	15 km/h	16.2 °C
May	13 mm	2	14 h/day	49 %	77 %	14 km/h	17.5 °C
June	3 mm	1	14 h/day	38 %	78 %	13 km/h	18.9 °C
July	2 mm	0	14 h/day	33 %	78 %	13 km/h	20.7 °C
August	1 mm	0	13 h/day	27 %	78 %	13 km/h	21.4 °C
September	4 mm	1	12 h/day	28 %	77 %	13 km/h	21.0 °C
October	18 mm	3	11 h/day	36 %	75 %	13 km/h	19.6 °C
November	26 mm	4	10 h/day	38 %	74 %	12 km/h	17.7 °C
December	56 mm	5	10.0 h/day	44 %	75 %	12 km/h	16.0 °C

How Oceanside compares

The same four figures for nearby destinations, so the numbers above have something to be read against. Summer high is the warmest month's average high; winter low is the coldest month's average low.

Destination	Summer high	Winter low	Rain per year	Days above 25 °C
Oceanside	26 °C	8.6 °C	372 mm	62
Escondido · United States	29 °C	5.9 °C	412 mm	134
San Diego · United States	25 °C	8.8 °C	311 mm	63
Irvine · United States	28 °C	8.6 °C	363 mm	125
Santa Ana · United States	27 °C	8.4 °C	355 mm	100
Huntington Beach · United States	26 °C	8.4 °C	310 mm	84

Where Oceanside ranks

Ranking	Position	Value
Places with the best weather in North America in June	6th of 50	95/100
Places with the best weather in North America year-round	8th of 50	88/100
Places with the best weather in North America in October	9th of 50	95/100
Places with the best weather in North America in July	13th of 50	91/100
Places with the best weather in North America in May	17th of 50	93/100
Places with the best weather in North America in August	18th of 50	88/100

Planning a trip? See the best time to visit Oceanside.

QuestionsCommon questions about Oceanside’s climate

When is the best time to visit Oceanside?

That depends on what you want, so the honest answer is a comparison rather than a single month. July, September, October sit closest to 20 °C on average, August is the warmest month and August the driest. The month-by-month table above has the full picture.

How hot does Oceanside get?

In August, the warmest month, daily highs average 26 °C. About 4 days a year pass 30 °C. The highest value in the 1991–2020 record is 37 °C.

How cold does it get in winter?

Nights average 8.6 °C in January, the coldest month. Freezing nights are not part of a normal year here.

Which month is wettest in Oceanside?

February, averaging 91 mm over 7 days with rain. The driest month is August with 1 mm. The year as a whole averages 372 mm.

Are these figures a forecast?

No. They are 1991–2020 climate normals: the average of thirty years, which describes what a month is usually like in Oceanside rather than what any particular week will bring. Individual years can differ substantially from the normal.

Data sources and method

ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
Open-Meteo — Open-Meteo.com. CC BY 4.0
NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
GeoNames — GeoNames.org. CC BY 4.0

Normal period: 1991–2020
Data point: 33.196°, -117.379° , 20 m above sea level (the coordinates the reanalysis values are taken for)
Dataset version: era5-1991-2020-scores1.1
Last processed: 1 August 2026

Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: monthly rankings, daylight hours, beach and comfort scores. Full formulas are on the methodology page.

Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.