Irvine weather in September: Irvine, California: normal highs, lows, rain and records for September
Irvine in September has a normal high of 89°F and a normal low of 62°F, a daily mean of 75°F, falling from 91°F on the 1st to 87°F by the 30th. Measurable precipitation falls on 0 days in a normal September, 0.10 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 32°C and low of 17°C, 3 mm of precipitation in September.
- NOAA stationIrvine Ranch
- Station IDUSC00044303
- Location33.72°N 117.72°W
- Elevation540 ft (165 m)
- From the center4 miles
- Population318,683
- Jan 69° 49°
- Feb 71° 48°
- Mar 73° 50°
- Apr 76° 52°
- May 79° 56°
- Jun 83° 59°
- Jul 88° 62°
- Aug 90° 62°
- Sep 89° 62°
- Oct 84° 58°
- Nov 76° 53°
- Dec 68° 48°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Irvine in September?
The normal high is 89°F and the normal low 62°F, for a daily mean of 75.3°F. September is 0.9°F cooler than August and 4.2°F warmer than October. September is the 2nd warmest month of the year in Irvine and the 9th wettest. Across the month the normal high falls 4°F, from 91°F on September 1 to 87°F on September 30. From one year to the next September's mean temperature typically moves about 1.9°F either way (NOAA's standard deviation), so roughly two Septembers in three average between 73°F and 77°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 4%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 91°F | 62°F | 1% | 1% |
| September 8 | 90°F | 62°F | 1% | 1% |
| September 15 | 89°F | 62°F | 2% | 2% |
| September 22 | 88°F | 61°F | 3% | 2% |
| September 30 | 87°F | 60°F | 4% | 3% |
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 | 91°F | 62°F | 1% | 1% | 12 h 50 min |
| September 2 | 91°F | 62°F | 1% | 1% | 12 h 50 min |
| September 3 | 90°F | 62°F | 1% | 1% | 12 h 50 min |
| September 4 | 90°F | 62°F | 1% | 1% | 12 h 50 min |
| September 5 | 90°F | 62°F | 1% | 1% | 12 h 50 min |
| September 6 | 90°F | 62°F | 1% | 1% | 12 h 40 min |
| September 7 | 90°F | 62°F | 1% | 1% | 12 h 40 min |
| September 8 | 90°F | 62°F | 1% | 1% | 12 h 40 min |
| September 9 | 90°F | 62°F | 1% | 1% | 12 h 40 min |
| September 10 | 90°F | 62°F | 1% | 1% | 12 h 40 min |
| September 11 | 90°F | 62°F | 1% | 1% | 12 h 30 min |
| September 12 | 90°F | 62°F | 2% | 1% | 12 h 30 min |
| September 13 | 89°F | 62°F | 2% | 1% | 12 h 30 min |
| September 14 | 89°F | 62°F | 2% | 1% | 12 h 30 min |
| September 15 | 89°F | 62°F | 2% | 2% | 12 h 30 min |
| September 16 | 89°F | 62°F | 2% | 2% | 12 h 20 min |
| September 17 | 89°F | 62°F | 2% | 2% | 12 h 20 min |
| September 18 | 89°F | 62°F | 2% | 2% | 12 h 20 min |
| September 19 | 88°F | 62°F | 2% | 2% | 12 h 20 min |
| September 20 | 88°F | 62°F | 2% | 2% | 12 h 20 min |
| September 21 | 88°F | 61°F | 3% | 2% | 12 h 10 min |
| September 22 | 88°F | 61°F | 3% | 2% | 12 h 10 min |
| September 23 | 88°F | 61°F | 3% | 2% | 12 h 10 min |
| September 24 | 88°F | 61°F | 3% | 2% | 12 h 10 min |
| September 25 | 87°F | 61°F | 3% | 2% | 12 h 10 min |
| September 26 | 87°F | 61°F | 3% | 3% | 12 h |
| September 27 | 87°F | 61°F | 3% | 3% | 12 h |
| September 28 | 87°F | 61°F | 4% | 3% | 12 h |
| September 29 | 87°F | 60°F | 4% | 3% | 12 h |
| September 30 | 87°F | 60°F | 4% | 3% | 11 h 50 min |
- Normal high
- 89°FSeptember average
- Normal low
- 62°FSeptember average
- Precipitation
- 0.10 inmonth total
- Days with precipitation
- fewer than 10.01 inch or more
- Days at 90°F or more
- 13
- Daylight
- 12 h 50 min to 11 h 50 minSeptember 1 to September 30
- Days at 70°F or more
- 30
- Days at 80°F or more
- 28
- Sunshine
- 91%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USC00044303; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Irvine in September?
On a given September day the chance of 0.01 inch or more is 2% on average, highest around September 30 (4%). In all, 0.10 in falls on 0 days of a normal September.
In a normal September in Irvine, 13 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00044303.
What are the records for September in Irvine?
The September mean against the 1991-2020 normal of 75.3°F: 2021 74.1°F (−1.2), 2022 79.2°F (+3.9), 2023 68.1°F (−7.2), 2024 73.9°F (−1.4), 2025 74.8°F (−0.5). 1 of 5 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 74.1°F | −1.2°F | 0.35 in |
| 2022 | 79.2°F | +3.9°F | 0.00 in |
| 2023 | 68.1°F | −7.2°F | 0.20 in |
| 2024 | 73.9°F | −1.4°F | 0.00 in |
| 2025 | 74.8°F | −0.5°F | 0.10 in |
Source: recent months: ACIS, station USC00044303. Records and recent months use complete months only.
How does September in Irvine 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; Irvine's is 89°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.