Oceanside, CA Climate & Monthly Averages
Oceanside has a semi-arid climate. August is the hottest month, averaging 76° by day; January is the coldest at 62°.
Sunshine is a defining feature of Oceanside's climate
8 months of the year in Oceanside land in the band most people call comfortable - highs between 18°C and 27°C with rain on fewer than twelve days. The exceptions sit at either end: August at 76°F (25°C) and January at 62°F (17°C).
How sun, temperature and rain fit together
January bottoms out at 62°F (17°C) in daylight, 49°F (9°C) after dark. At its warmest, in August, Oceanside runs to 76°F (25°C) in the afternoon and back to 67°F (19°C) by dawn. The gridded 2015-2024 daily record for this location tops out at 98°F (37°C) and bottoms at 38°F (3°C) - decade extremes, not all-time station records.
Sunshine averages 10.6 hours a day over the year - sunnier than roughly 85% of the cities we track, peaking in July at 13.0 hours.
Precipitation concentrates in January - 3.2 inches (81 mm) on 6 days - and thins out by June. Days and nights are about 6°C apart on average - narrower than about 88% of the cities we track. 6 months average under 20 mm of rain, the longest unbroken stretch running May through October.
More climate facts for Oceanside
- Hottest month: August - highs near 76°F (25°C)
- Coldest month: January - highs near 62°F (17°C)
- Decade extremes (2015-2024): 98°F (37°C) high · 38°F (3°C) low
- Wettest month: January (6 rainy days) · Sunniest: July (13.0 h sun/day)
- Climate type: semi-arid
- Annual swing: 9°C between the average warmest and coolest month · day to night: 6°C
- Average humidity: 76%
The most comfortable sunny-weather window
Best time to visit Oceanside
April to July and January to February is the sweet spot for Oceanside - temperatures sit either side of the peak heat rather than in it. Expect 67°F (19°C) in the afternoon and around 4 days of rain in a typical month of it. For the same question asked the other way round, see where else is warm in April.
What to pack
Pack for Oceanside with light layers that can absorb a mild swing through the day. August nights average 67°F (19°C), so evenings rarely match the afternoons.
Monthly climate table
| Month | High | Low | Rain days | Precipitation | Sunshine | Daylight | Wet-day chance | Humidity |
|---|---|---|---|---|---|---|---|---|
| January | 62° | 49° | 6 | 3.2 in | 8.6 h/day | 10.2 h | 19% | 74% |
| February | 63° | 49° | 6 | 2.8 in | 9.3 h/day | 11.0 h | 21% | 72% |
| March | 63° | 51° | 9 | 2.8 in | 10.4 h/day | 11.9 h | 28% | 78% |
| April | 65° | 54° | 4 | 0.8 in | 11.2 h/day | 13.0 h | 13% | 77% |
| May | 66° | 57° | 4 | 0.8 in | 11.6 h/day | 13.9 h | 13% | 78% |
| June | 71° | 62° | 1 | 0.1 in | 12.4 h/day | 14.3 h | 3% | 79% |
| July | 75° | 66° | 1 | 0.1 in | 13.0 h/day | 14.1 h | 2% | 80% |
| August | 76° | 67° | 1 | 0.3 in | 12.1 h/day | 13.4 h | 2% | 80% |
| September | 76° | 66° | 2 | 0.5 in | 11.0 h/day | 12.3 h | 6% | 79% |
| October | 74° | 61° | 3 | 0.5 in | 10.2 h/day | 11.3 h | 9% | 74% |
| November | 68° | 54° | 4 | 1.1 in | 9.5 h/day | 10.4 h | 13% | 67% |
| December | 63° | 49° | 5 | 2.4 in | 8.3 h/day | 10.0 h | 17% | 70% |
Oceanside month by month
Each card shows the average high and low. The bar places that month between Oceanside's coldest night and warmest afternoon.
January
- Rain
- 6 days
- Sunshine
- 8.6 h
- Daylight
- 10.2 h
February
- Rain
- 6 days
- Sunshine
- 9.3 h
- Daylight
- 11.0 h
March
- Rain
- 9 days
- Sunshine
- 10.4 h
- Daylight
- 11.9 h
April
- Rain
- 4 days
- Sunshine
- 11.2 h
- Daylight
- 13.0 h
May
- Rain
- 4 days
- Sunshine
- 11.6 h
- Daylight
- 13.9 h
June
- Rain
- 1 day
- Sunshine
- 12.4 h
- Daylight
- 14.3 h
July
- Rain
- 1 day
- Sunshine
- 13.0 h
- Daylight
- 14.1 h
August
- Rain
- 1 day
- Sunshine
- 12.1 h
- Daylight
- 13.4 h
September
- Rain
- 2 days
- Sunshine
- 11.0 h
- Daylight
- 12.3 h
October
- Rain
- 3 days
- Sunshine
- 10.2 h
- Daylight
- 11.3 h
November
- Rain
- 4 days
- Sunshine
- 9.5 h
- Daylight
- 10.4 h
December
- Rain
- 5 days
- Sunshine
- 8.3 h
- Daylight
- 10.0 h
Looking for warmer alternatives? Browse warm places by month, or compare Oceanside's coolest part of the year: January, February, March.
Seasonal weather under Oceanside's sunnier skies
Spring (March through May)
Through spring, Oceanside runs cool rather than cold: 65°F (18°C) by day, 54°F (12°C) after dark, and rain comes on about 16 days over the three months. Daylight is generous - around 11.1 hours of sun a day.
Summer (June through August)
Through summer, Oceanside brings comfortable warmth: 74°F (23°C) by day, 65°F (18°C) after dark, and precipitation is sparse, near 13 mm (0.5 in) for the season. Daylight is generous - around 12.5 hours of sun a day.
Fall (September through November)
Through fall, Oceanside is pleasantly warm: 73°F (23°C) by day, 60°F (16°C) after dark, and rain comes on about 8 days over the three months. Daylight is generous - around 10.2 hours of sun a day.
Winter (December through February)
Through winter, Oceanside is crisp but comfortable: 63°F (17°C) by day, 49°F (9°C) after dark, and rain comes on about 17 days over the three months.
How unusual is Oceanside?
- Rain or snow reaches the ground on 45 days a year - fewer wet days than all but 7% of the 3496 cities we track.
- Annual precipitation is 15.4 inches (391 mm) - drier than all but 11% of the 3496 cities we track.
- 57% of the year's precipitation falls in its wettest three months - more seasonal than 88% of the 3496 cities we track.
These comparisons use the same ten-year window for every city in the dataset.
Oceanside temperature extremes in the 2015–2024 dataset
Derived from ERA5 reanalysis data, 2015–2024. Official station records may differ. Need another precipitation unit? Use the rainfall converter.