New Haven weather in September: New Haven, Connecticut: normal highs, lows, rain and records for September
New Haven in September has a normal high of 75°F and a normal low of 57°F, a daily mean of 66°F, falling from 79°F on the 1st to 70°F by the 30th. Measurable precipitation falls on 9 days in a normal September, 4.03 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 24°C and low of 14°C, 102 mm of precipitation in September.
- NOAA stationNew Haven Tweed Airport
- Station IDUSW00014758
- Location41.26°N 72.89°W
- Elevation3 ft (1 m)
- From the center4 miles
- Population137,562
- Jan 38° 23°
- Feb 40° 24°
- Mar 47° 30°
- Apr 58° 39°
- May 68° 49°
- Jun 76° 59°
- Jul 82° 66°
- Aug 81° 65°
- Sep 75° 57°
- Oct 64° 46°
- Nov 53° 36°
- Dec 44° 29°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is New Haven in September?
The normal high is 75°F and the normal low 57°F, for a daily mean of 66.0°F. September is 6.9°F cooler than August and 11.3°F warmer than October. September is the 4th warmest month of the year in New Haven and the 2nd wettest. Across the month the normal high falls 9°F, from 79°F on September 1 to 70°F on September 30. From one year to the next September's mean temperature typically moves about 2.0°F either way (NOAA's standard deviation), so roughly two Septembers in three average between 64°F and 68°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 35%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 79°F | 62°F | 30% | 17% |
| September 8 | 77°F | 60°F | 30% | 16% |
| September 15 | 75°F | 58°F | 31% | 16% |
| September 22 | 73°F | 55°F | 32% | 17% |
| September 30 | 70°F | 52°F | 35% | 18% |
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 | 79°F | 62°F | 30% | 17% | 13 h 10 min |
| September 2 | 79°F | 62°F | 30% | 17% | 13 h 10 min |
| September 3 | 78°F | 61°F | 30% | 17% | 13 h |
| September 4 | 78°F | 61°F | 30% | 17% | 13 h |
| September 5 | 78°F | 61°F | 30% | 17% | 13 h |
| September 6 | 78°F | 61°F | 30% | 17% | 13 h |
| September 7 | 77°F | 60°F | 30% | 16% | 12 h 50 min |
| September 8 | 77°F | 60°F | 30% | 16% | 12 h 50 min |
| September 9 | 77°F | 60°F | 30% | 16% | 12 h 50 min |
| September 10 | 77°F | 59°F | 30% | 16% | 12 h 50 min |
| September 11 | 76°F | 59°F | 30% | 16% | 12 h 40 min |
| September 12 | 76°F | 59°F | 30% | 16% | 12 h 40 min |
| September 13 | 76°F | 58°F | 30% | 16% | 12 h 40 min |
| September 14 | 75°F | 58°F | 31% | 16% | 12 h 40 min |
| September 15 | 75°F | 58°F | 31% | 16% | 12 h 30 min |
| September 16 | 75°F | 57°F | 31% | 16% | 12 h 30 min |
| September 17 | 75°F | 57°F | 31% | 16% | 12 h 30 min |
| September 18 | 74°F | 57°F | 31% | 16% | 12 h 20 min |
| September 19 | 74°F | 56°F | 32% | 16% | 12 h 20 min |
| September 20 | 73°F | 56°F | 32% | 17% | 12 h 20 min |
| September 21 | 73°F | 56°F | 32% | 17% | 12 h 20 min |
| September 22 | 73°F | 55°F | 32% | 17% | 12 h 10 min |
| September 23 | 72°F | 55°F | 33% | 17% | 12 h 10 min |
| September 24 | 72°F | 54°F | 33% | 17% | 12 h 10 min |
| September 25 | 72°F | 54°F | 33% | 17% | 12 h 10 min |
| September 26 | 71°F | 54°F | 34% | 18% | 12 h |
| September 27 | 71°F | 53°F | 34% | 18% | 12 h |
| September 28 | 71°F | 53°F | 34% | 18% | 12 h |
| September 29 | 70°F | 52°F | 34% | 18% | 11 h 50 min |
| September 30 | 70°F | 52°F | 35% | 18% | 11 h 50 min |
- Normal high
- 75°FSeptember average
- Normal low
- 57°FSeptember average
- Precipitation
- 4.03 inmonth total
- Days with precipitation
- 90.01 inch or more
- Daylight
- 13 h 10 min to 11 h 50 minSeptember 1 to September 30
- Days at 70°F or more
- 25
- Days at 80°F or more
- 8
- Sunshine
- 78%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00014758; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in New Haven in September?
On a given September day the chance of 0.01 inch or more is 31% on average, highest around September 30 (35%). In all, 4.03 in falls on 9 days of a normal September, 1 of them with an inch or more.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00014758.
What are the records for September in New Haven?
The warmest September temperature on this station's record (since 1948) is 95°F, on September 7, 2023; the coldest is 34°F, on September 28, 1957. The wettest September brought 9.30 in (2004).
The September mean against the 1991-2020 normal of 66.0°F: 2021 70.1°F (+4.1), 2022 68.7°F (+2.7), 2023 69.2°F (+3.2), 2024 67.7°F (+1.7), 2026 66.1°F (+0.1). 5 of 5 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 70.1°F | +4.1°F | 7.18 in |
| 2022 | 68.7°F | +2.7°F | 2.54 in |
| 2023 | 69.2°F | +3.2°F | 6.95 in |
| 2024 | 67.7°F | +1.7°F | 1.16 in |
| 2026 | 66.1°F | +0.1°F | – |
Source: records: ACIS, station USW00014758; recent months: ACIS, station USW00014758. Records and recent months use complete months only.
How does September in New Haven compare across Connecticut?
Across the 13 places PlainClimate covers in Connecticut, September normal highs run from 69°F in Norfolk to 76°F in Hartford; New Haven's is 75°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.
Other months and places
- New Haven in August81°F by day, 65°F at night
- New Haven in October64°F by day, 46°F at night
- New Haven through the yearEvery month, frost dates, records and recent years
- Connecticut in SeptemberThe statewide normal and the warmest and coolest places
- Hartford: Connecticut's warmest Septembernormal high 76°F