September
September · June · May
80climate match
United States · 1991–2020
Best time to visit
Whippany.
September leads for comfortable weather in Whippany: typically 24.9°C by day, 12.4°C at night, with 97 mm of rain. Based on measured 1991–2020 NOAA station history.
Best comfortSeptember
Typical high24.9°C
Typical low12.4°C
Rain in September97 mm
August
August · July · June
68climate match
May
May · October · September
72climate match
The weakest month is January, scoring 5 against September’s 80 — days reach only 3.4°C, 21° 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
53.4° / -6.1°
Feb
54.7° / -5.6°
Mar
99.4° / -1.4°
Apr
4016.3° / 4.2°
May
6822.2° / 9.8°
Jun
7026.9° / 14.9°
Jul
5829.9° / 17.8°
Aug
6728.8° / 16.5°
Sep
8024.9° / 12.4°
Oct
4818.3° / 6.4°
Nov
2311.7° / 1°
Dec
56.1° / -2.7°
| Month | Day | Night | Rain | Wet days | Daylight | Comfort | Coverage |
|---|---|---|---|---|---|---|---|
| January | 3.4°C | -6.1°C | 87 mm | 8 | 9 h 33 | 5 | Good coverage |
| February | 4.7°C | -5.6°C | 61 mm | 7.2 | 10 h 34 | 5 | Good coverage |
| March | 9.4°C | -1.4°C | 94 mm | 8.7 | 11 h 49 | 9 | Strong coverage |
| April | 16.3°C | 4.2°C | 103 mm | 9.5 | 13 h 14 | 40 | Strong coverage |
| May | 22.2°C | 9.8°C | 105 mm | 10.1 | 14 h 26 | 68 | Good coverage |
| June | 26.9°C | 14.9°C | 131 mm | 10.6 | 15 h 05 | 70 | Good coverage |
| July | 29.9°C | 17.8°C | 119 mm | 9.5 | 14 h 50 | 58 | Strong coverage |
| August | 28.8°C | 16.5°C | 105 mm | 8.7 | 13 h 48 | 67 | Good coverage |
| September | 24.9°C | 12.4°C | 97 mm | 7.1 | 12 h 25 | 80 | Strong coverage |
| October | 18.3°C | 6.4°C | 126 mm | 8.5 | 11 h 02 | 48 | Good coverage |
| November | 11.7°C | 1°C | 90 mm | 6.6 | 9 h 51 | 23 | Strong coverage |
| December | 6.1°C | -2.7°C | 108 mm | 8.7 | 9 h 15 | 5 | Strong coverage |
What has changed
Whippany runs +1.2°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
+1.4
Feb
+1.8
Mar
+1.1
Apr
+1.1
May
+0.7
Jun
+1.0
Jul
+1.8
Aug
+1.1
Sep
+1.3
Oct
+0.8
Nov
+0.2
Dec
+1.8
| Month | Record high | Record low | Wettest day | Wettest / driest month | Years |
|---|---|---|---|---|---|
| January | 21.7°C16 Jan 1932 | -26.1°C22 Jan 1961 | 77 mm10 Jan 2024 | 295 mm1979 · driest 10 mm in 1970 | 115 |
| February | 23.9°C22 Feb 2018 | -28.9°C9 Feb 1934 | 84 mm6 Feb 1896 | 212 mm1896 · driest 15 mm in 1895 | 114 |
| March | 28.3°C29 Mar 1945 | -19.4°C1 Mar 1934 | 89 mm22 Mar 1980 | 250 mm2010 · driest 20 mm in 1915 | 114 |
| April | 33.9°C18 Apr 2002 | -13.3°C1 Apr 1923 | 93 mm16 Apr 2007 | 273 mm1983 · driest 25 mm in 1985 | 115 |
| May | 36.7°C15 May 1900 | -3.3°C11 May 1923 | 86 mm1 May 2014 | 285 mm1990 · driest 19 mm in 1955 | 113 |
| June | 37.2°C5 Jun 1925 | 0.0°C1 Jun 1930 | 95 mm6 Jun 1992 | 352 mm1972 · driest 12 mm in 1949 | 113 |
| July | 38.9°C23 Jul 2011 | 5.6°C16 Jul 1929 | 189 mm23 Jul 1919 | 359 mm1919 · driest 8 mm in 2005 | 114 |
| August | 39.4°C8 Aug 1918 | 2.2°C31 Aug 1965 | 126 mm13 Aug 1955 | 298 mm2018 · driest 12 mm in 1964 | 112 |
| September | 40.0°C3 Sep 1953 | -1.7°C25 Sep 1963 | 141 mm22 Sep 1966 | 314 mm1934 · driest 6 mm in 2005 | 113 |
| October | 32.2°C3 Oct 2019 | -8.9°C28 Oct 1936 | 150 mm9 Oct 2005 | 377 mm2005 · driest 0 mm in 2024 | 113 |
| November | 26.7°C14 Nov 1931 | -14.4°C26 Nov 1938 | 88 mm9 Nov 1972 | 254 mm1932 · driest 8 mm in 1933 | 113 |
| December | 25.0°C1 Dec 1933 | -29.4°C30 Dec 1917 | 91 mm18 Dec 2023 | 253 mm2023 · driest 5 mm in 1955 | 113 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 27 | 3 | 2 |
| February | 0 | 0 | 24 | 2 | 2 |
| March | <1 | 0 | 19 | 3 | 2 |
| April | 3 | <1 | 5 | 3 | <1 |
| May | 10 | 3 | <1 | 4 | 0 |
| June | 21 | 7 | 0 | 4 | 0 |
| July | 29 | 16 | 0 | 4 | 0 |
| August | 28 | 13 | 0 | 4 | 0 |
| September | 15 | 4 | 0 | 3 | 0 |
| October | 3 | <1 | 4 | 4 | 0 |
| November | 0 | 0 | 14 | 3 | <1 |
| December | 0 | 0 | 24 | 4 | 1 |
The best month has moved. On the 1961–1990 numbers the strongest month here was June (scoring 82); on 2011–2025 it is September (84). 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% | 26% | 9% | 28% | -0.2–5.7°C |
| February | <1% | 27% | 10% | 30% | 0.8–6.8°C |
| March | 4% | 28% | 10% | 33% | 6.1–11.6°C |
| April | 19% | 31% | 11% | 39% | 13.3–17.7°C |
| May | 48% | 33% | 11% | 42% | 19.5–23.7°C |
| June | 67% | 30% | 12% | 36% | 24.7–28.1°C |
| July | 70% | 29% | 12% | 33% | 27.6–30.8°C |
| August | 72% | 28% | 12% | 29% | 26.5–29.8°C |
| September | 67% | 24% | 10% | 23% | 22.4–26.4°C |
| October | 31% | 23% | 10% | 23% | 15.9–20.5°C |
| November | 5% | 24% | 11% | 24% | 9.3–13.9°C |
| December | <1% | 26% | 11% | 27% | 1.9–8.1°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 5106365
- NOAA station
- USC00280907 · BOONTON 1 SE
- Station distance
- 7.7 km from the place centre
- Climate period
- 1991–2020
- Minimum month coverage
- 23 usable years
- Daylight
- Calculated from latitude 40.82°, 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.