September
September · May · June
76climate match
United States · 1991–2020
Best time to visit
Trenton.
September leads for comfortable weather in Trenton: typically 26.6°C by day, 13°C at night, with 98 mm of rain. Based on measured 1991–2020 NOAA station history.
Best comfortSeptember
Typical high26.6°C
Typical low13°C
Rain in September98 mm
July
July · August · June
71climate match
October
October · April · September
79climate match
The weakest month is January, scoring 5 against September’s 76 — days reach only 2°C, 22° below the 24°C the score treats as ideal.
Month by month
The whole year,
without the guesswork.
The bars show the comfort score. Day and night temperatures come from daily observed highs and lows; rain is the historical monthly estimate.
Jan
52° / -8.5°
Feb
54.5° / -6.9°
Mar
2011.2° / -1°
Apr
4918.1° / 5°
May
7023.9° / 11.5°
Jun
6029.3° / 17.2°
Jul
5331.7° / 19.5°
Aug
5830.6° / 17.9°
Sep
7626.6° / 13°
Oct
5819.2° / 6°
Nov
2911.9° / -0.2°
Dec
54.1° / -6°
| Month | Day | Night | Rain | Wet days | Daylight | Comfort | Coverage |
|---|---|---|---|---|---|---|---|
| January | 2°C | -8.5°C | 32 mm | 4.2 | 9 h 37 | 5 | Good coverage |
| February | 4.5°C | -6.9°C | 47 mm | 5.7 | 10 h 37 | 5 | Good coverage |
| March | 11.2°C | -1°C | 69 mm | 7.5 | 11 h 49 | 20 | Good coverage |
| April | 18.1°C | 5°C | 93 mm | 8.9 | 13 h 12 | 49 | Good coverage |
| May | 23.9°C | 11.5°C | 155 mm | 10.2 | 14 h 22 | 70 | Good coverage |
| June | 29.3°C | 17.2°C | 134 mm | 8.5 | 15 h 00 | 60 | Good coverage |
| July | 31.7°C | 19.5°C | 100 mm | 7.4 | 14 h 45 | 53 | Good coverage |
| August | 30.6°C | 17.9°C | 117 mm | 7.4 | 13 h 45 | 58 | Good coverage |
| September | 26.6°C | 13°C | 98 mm | 5.8 | 12 h 24 | 76 | Good coverage |
| October | 19.2°C | 6°C | 80 mm | 6.5 | 11 h 04 | 58 | Good coverage |
| November | 11.9°C | -0.2°C | 51 mm | 4.9 | 9 h 54 | 29 | Good coverage |
| December | 4.1°C | -6°C | 46 mm | 5.1 | 9 h 20 | 5 | Good coverage |
What has changed
Trenton runs +0.5°C
on the 1961–1990 baseline.
Each bar compares the 2011–2025 daytime average for that month against the same month in 1961–1990, measured at the same station. Months where the older record is too thin to compare are left blank.
Jan
+0.9
Feb
0.0
Mar
+0.6
Apr
-1.1
May
0.0
Jun
+1.3
Jul
0.0
Aug
0.0
Sep
+1.6
Oct
+0.1
Nov
+0.5
Dec
+1.9
| Month | Record high | Record low | Wettest day | Wettest / driest month | Years |
|---|---|---|---|---|---|
| January | 20.6°C14 Jan 1952 | -32.2°C22 Jan 1930 | 72 mm13 Jan 1911 | 108 mm1949 · driest 0 mm in 1928 | 119 |
| February | 27.8°C24 Feb 1930 | -31.7°C13 Feb 1905 | 102 mm20 Feb 1913 | 184 mm1911 · driest 1 mm in 1947 | 119 |
| March | 33.3°C22 Mar 2026 | -26.1°C5 Mar 1978 | 72 mm24 Mar 1920 | 178 mm1973 · driest 5 mm in 1918 | 120 |
| April | 34.4°C10 Apr 1930 | -12.8°C2 Apr 2018 | 97 mm15 Apr 1921 | 211 mm1929 · driest 14 mm in 2018 | 121 |
| May | 40.6°C30 May 1934 | -5.6°C4 May 1907 | 114 mm3 May 1919 | 393 mm1982 · driest 15 mm in 1914 | 118 |
| June | 41.7°C29 Jun 1936 | 5.6°C1 Jun 1983 | 133 mm25 Jun 2008 | 466 mm1947 · driest 11 mm in 1968 | 121 |
| July | 45.6°C15 Jul 1936 | 7.8°C24 Jul 2003 | 160 mm13 Jul 2017 | 404 mm1922 · driest 5 mm in 1930 | 120 |
| August | 45.0°C16 Aug 1936 | 5.6°C30 Aug 1915 | 128 mm2 Aug 1939 | 266 mm1977 · driest 1 mm in 2013 | 117 |
| September | 41.1°C7 Sep 1939 | -2.8°C28 Sep 1942 | 169 mm7 Sep 1914 | 306 mm1911 · driest 7 mm in 1906 | 117 |
| October | 36.7°C7 Oct 1939 | -16.1°C30 Oct 1925 | 128 mm4 Oct 1998 | 252 mm1941 · driest 3 mm in 1952 | 118 |
| November | 28.9°C2 Nov 1938 | -21.1°C30 Nov 1964 | 75 mm2 Nov 1961 | 226 mm1931 · driest 0 mm in 1917 | 119 |
| December | 23.3°C16 Dec 2021 | -31.1°C19 Dec 1983 | 78 mm26 Dec 1942 | 139 mm1982 · driest 1 mm in 1919 | 118 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 28 | 1 | 3 |
| February | <1 | 0 | 24 | 1 | 3 |
| March | 1 | 0 | 19 | 2 | 1 |
| April | 6 | <1 | 6 | 3 | <1 |
| May | 14 | 4 | <1 | 4 | <1 |
| June | 25 | 15 | 0 | 4 | 0 |
| July | 29 | 21 | 0 | 3 | 0 |
| August | 28 | 18 | 0 | 4 | 0 |
| September | 20 | 9 | 0 | 3 | 0 |
| October | 7 | 1 | 5 | 2 | <1 |
| November | <1 | 0 | 16 | 2 | <1 |
| December | 0 | 0 | 26 | 2 | 3 |
The best month has moved. On the 1961–1990 numbers the strongest month here was May (scoring 80); on 2011–2025 it is September (83). Both are scored the same way, from the same station — only the climate underneath changed.
| Month | Warm & dry days | Wet days | Washouts | Week with 3+ wet days | Daytime mean has ranged |
|---|---|---|---|---|---|
| January | <1% | 14% | 4% | 10% | -2.7–5.4°C |
| February | 2% | 17% | 4% | 12% | -0.3–9.0°C |
| March | 12% | 22% | 7% | 22% | 7.3–15.2°C |
| April | 32% | 26% | 10% | 31% | 15.2–21.2°C |
| May | 55% | 31% | 12% | 39% | 21.5–26.3°C |
| June | 71% | 28% | 13% | 33% | 26.5–31.3°C |
| July | 79% | 22% | 9% | 19% | 29.2–34.1°C |
| August | 76% | 24% | 11% | 24% | 28.2–33.3°C |
| September | 71% | 23% | 11% | 22% | 23.8–29.2°C |
| October | 45% | 20% | 8% | 17% | 17.0–22.3°C |
| November | 10% | 16% | 6% | 12% | 7.9–14.2°C |
| December | <1% | 16% | 5% | 11% | 0.4–7.7°C |
A warm and dry day reaches 20°C with under 1 mm of rain; a wet day gets 1 mm or more; a washout gets 10 mm or more. The week column is the share of seven-day stretches in that month, across the station’s whole daily record, that contained three or more wet days — the odds a week-long trip is rained on repeatedly, counted rather than modelled. The last column is the 10th to 90th percentile of that month’s daytime average across individual years: a narrow band means the average is what you will get, a wide one means the average is a midpoint between years that felt quite different.
The evidence behind this page
Nearby, measured,
and named.
- Place identity
- GeoNames 5057562
- NOAA station
- USC00238444 · TRENTON
- Station distance
- 0.8 km from the place centre
- Climate period
- 1991–2020
- Minimum month coverage
- 22 usable years
- Daylight
- Calculated from latitude 40.08°, mid-month, sunrise to sunset including refraction. Not a station measurement.
- Important limit
- Historical climate is not a forecast. Nearby stations can miss mountains, coasts, and local microclimates.