San Diego weather in September: San Diego, California: normal highs, lows, rain and records for September
San Diego in September has a normal high of 77°F and a normal low of 66°F, a daily mean of 72°F, falling from 78°F on the 1st to 76°F by the 30th. Measurable precipitation falls on 1 days in a normal September, 0.12 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 25°C and low of 19°C, 3 mm of precipitation in September.
- NOAA stationSan Diego Lindbergh Field
- Station IDUSW00023188
- Location32.73°N 117.18°W
- Elevation15 ft (5 m)
- From the center6 miles
- Population1,404,452
- Jan 66° 50°
- Feb 66° 52°
- Mar 67° 55°
- Apr 69° 57°
- May 70° 60°
- Jun 72° 63°
- Jul 75° 66°
- Aug 77° 68°
- Sep 77° 66°
- Oct 75° 62°
- Nov 71° 55°
- Dec 66° 50°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is San Diego in September?
The normal high is 77°F and the normal low 66°F, for a daily mean of 71.7°F. September is 0.7°F cooler than August and 3.6°F warmer than October. September is the 2nd warmest month of the year in San Diego and the 9th wettest. Across the month the normal high falls 2°F, from 78°F on September 1 to 76°F on September 30. From one year to the next September's mean temperature typically moves about 2.3°F either way (NOAA's standard deviation), so roughly two Septembers in three average between 69°F and 74°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 5%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 78°F | 67°F | 2% | 0% |
| September 8 | 78°F | 67°F | 3% | 1% |
| September 15 | 77°F | 66°F | 3% | 1% |
| September 22 | 77°F | 66°F | 4% | 1% |
| September 30 | 76°F | 64°F | 5% | 2% |
Every day of September: normal high, low and chance of precipitation (warmest afternoon September 1, coldest night September 30)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| September 1 | 78°F | 67°F | 2% | 0% | 12 h 50 min |
| September 2 | 78°F | 67°F | 2% | 0% | 12 h 50 min |
| September 3 | 78°F | 67°F | 2% | 0% | 12 h 50 min |
| September 4 | 78°F | 67°F | 2% | 1% | 12 h 50 min |
| September 5 | 78°F | 67°F | 2% | 1% | 12 h 40 min |
| September 6 | 78°F | 67°F | 2% | 1% | 12 h 40 min |
| September 7 | 78°F | 67°F | 3% | 1% | 12 h 40 min |
| September 8 | 78°F | 67°F | 3% | 1% | 12 h 40 min |
| September 9 | 78°F | 67°F | 3% | 1% | 12 h 40 min |
| September 10 | 78°F | 67°F | 3% | 1% | 12 h 40 min |
| September 11 | 78°F | 67°F | 3% | 1% | 12 h 30 min |
| September 12 | 78°F | 67°F | 3% | 1% | 12 h 30 min |
| September 13 | 78°F | 67°F | 3% | 1% | 12 h 30 min |
| September 14 | 78°F | 67°F | 3% | 1% | 12 h 30 min |
| September 15 | 77°F | 66°F | 3% | 1% | 12 h 30 min |
| September 16 | 77°F | 66°F | 3% | 1% | 12 h 20 min |
| September 17 | 77°F | 66°F | 3% | 1% | 12 h 20 min |
| September 18 | 77°F | 66°F | 3% | 1% | 12 h 20 min |
| September 19 | 77°F | 66°F | 4% | 1% | 12 h 20 min |
| September 20 | 77°F | 66°F | 4% | 1% | 12 h 20 min |
| September 21 | 77°F | 66°F | 4% | 1% | 12 h 10 min |
| September 22 | 77°F | 66°F | 4% | 1% | 12 h 10 min |
| September 23 | 77°F | 66°F | 4% | 1% | 12 h 10 min |
| September 24 | 77°F | 65°F | 4% | 1% | 12 h 10 min |
| September 25 | 76°F | 65°F | 4% | 1% | 12 h 10 min |
| September 26 | 76°F | 65°F | 4% | 1% | 12 h |
| September 27 | 76°F | 65°F | 4% | 1% | 12 h |
| September 28 | 76°F | 65°F | 5% | 2% | 12 h |
| September 29 | 76°F | 65°F | 5% | 2% | 12 h |
| September 30 | 76°F | 64°F | 5% | 2% | 12 h |
- Normal high
- 77°FSeptember average
- Normal low
- 66°FSeptember average
- Precipitation
- 0.12 inmonth total
- Days with precipitation
- 10.01 inch or more
- Days at 90°F or more
- 1
- Daylight
- 12 h 50 min to 12 hSeptember 1 to September 30
- Days at 70°F or more
- 29
- Days at 80°F or more
- 8
- Sunshine
- 82%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00023188; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in San Diego in September?
On a given September day the chance of 0.01 inch or more is 3% on average, highest around September 30 (5%). In all, 0.12 in falls on 1 days of a normal September.
In a normal September in San Diego, 1 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00023188.
How humid and windy is San Diego in September?
At 3 p.m. the normal temperature is 74°F with 60% relative humidity and a dew point of 59°F; at 6 a.m. it is 65°F with 77% humidity. The wind averages 5.8 mph, most often from the west-northwest in the afternoon.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 65°F | 58°F | 77% | 3.6 mph | 32% |
| 9 a.m. | 71°F | 58°F | 65% | 5.2 mph | 44% |
| noon | 74°F | 59°F | 58% | 10.0 mph | 57% |
| 3 p.m. | 74°F | 59°F | 60% | 10.0 mph | 56% |
| 6 p.m. | 70°F | 60°F | 70% | 6.8 mph | 53% |
| 9 p.m. | 68°F | 60°F | 75% | 4.2 mph | 56% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00023188. Hourly normals exist only for NOAA's first-order stations; a dash where NOAA publishes no value for that hour (the sky at some hours).
What are the records for September in San Diego?
The warmest September temperature on San Diego's official record (since 1874) is 111°F, on September 26, 1963; the coldest is 50°F, on September 29, 1880. The wettest September brought 3.14 in (1939).
The September mean against the 1991-2020 normal of 71.7°F: 2021 72.5°F (+0.8), 2022 75.6°F (+3.9), 2023 70.9°F (−0.8), 2024 72.1°F (+0.4), 2025 72.1°F (+0.4), 2026 74.8°F (+3.1). 5 of 6 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 72.5°F | +0.8°F | 0.50 in |
| 2022 | 75.6°F | +3.9°F | 0.65 in |
| 2023 | 70.9°F | −0.8°F | 0.05 in |
| 2024 | 72.1°F | +0.4°F | 0.02 in |
| 2025 | 72.1°F | +0.4°F | 0.46 in |
| 2026 | 74.8°F | +3.1°F | 0.02 in |
Source: records: ACIS, NWS threaded record SANthr; recent months: ACIS, station USW00023188. Records and recent months use complete months only.
How does September in San Diego compare across California?
Across the 219 places PlainClimate covers in California, September normal highs run from 64°F in Eureka to 104°F in Brawley; San Diego's is 77°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.
Other months and places
- San Diego in August77°F by day, 68°F at night
- San Diego in October75°F by day, 62°F at night
- San Diego through the yearEvery month, frost dates, records and recent years
- California in SeptemberThe statewide normal and the warmest and coolest places
- Brawley: California's warmest Septembernormal high 104°F