September
September · June · August
78climate match
United States · 1991–2020
Best time to visit
Delafield.
September leads for comfortable weather in Delafield: typically 23°C by day, 10.9°C at night, with 86 mm of rain. Based on measured 1991–2020 NOAA station history.
Best comfortSeptember
Typical high23°C
Typical low10.9°C
Rain in September86 mm
July
July · August · June
65climate match
May
May · September · October
76climate match
The weakest month is January, scoring 5 against September’s 78 — days reach only -2.4°C, 26° 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
5-2.4° / -11.6°
Feb
5-0.3° / -10.2°
Mar
56.3° / -4.2°
Apr
2713.4° / 2.1°
May
5920.1° / 8.5°
Jun
7525.5° / 13.9°
Jul
7227.6° / 16.2°
Aug
7526.8° / 15.4°
Sep
7823° / 10.9°
Oct
4415.8° / 4.4°
Nov
97.6° / -1.9°
Dec
50.7° / -7.8°
| Month | Day | Night | Rain | Wet days | Sea | Daylight | Comfort | Coverage |
|---|---|---|---|---|---|---|---|---|
| January | -2.4°C | -11.6°C | 42 mm | 7.1 | 3.3°C | 9 h 20 | 5 | Strong coverage |
| February | -0.3°C | -10.2°C | 41 mm | 6.5 | 2.1°C | 10 h 27 | 5 | Strong coverage |
| March | 6.3°C | -4.2°C | 53 mm | 7.3 | 2.0°C | 11 h 47 | 5 | Strong coverage |
| April | 13.4°C | 2.1°C | 98 mm | 9.7 | 3.2°C | 13 h 20 | 27 | Strong coverage |
| May | 20.1°C | 8.5°C | 105 mm | 10.5 | 5.8°C | 14 h 38 | 59 | Strong coverage |
| June | 25.5°C | 13.9°C | 123 mm | 9.3 | 12.3°C | 15 h 21 | 75 | Strong coverage |
| July | 27.6°C | 16.2°C | 105 mm | 7.9 | 19.3°C | 15 h 04 | 72 | Strong coverage |
| August | 26.8°C | 15.4°C | 106 mm | 8.4 | 21.1°C | 13 h 56 | 75 | Strong coverage |
| September | 23°C | 10.9°C | 86 mm | 7.6 | 18.8°C | 12 h 26 | 78 | Strong coverage |
| October | 15.8°C | 4.4°C | 72 mm | 7.8 | 13.1°C | 10 h 57 | 44 | Strong coverage |
| November | 7.6°C | -1.9°C | 56 mm | 6.8 | 8.0°C | 9 h 39 | 9 | Strong coverage |
| December | 0.7°C | -7.8°C | 48 mm | 7.5 | 5.1°C | 9 h 01 | 5 | Strong coverage |
What has changed
Delafield runs +0.6°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
+1.5
Feb
+0.4
Mar
+1.1
Apr
-0.9
May
-0.4
Jun
+0.1
Jul
-0.4
Aug
+0.1
Sep
+1.5
Oct
+0.9
Nov
+0.7
Dec
+2.8
| Month | Record high | Record low | Wettest day | Wettest / driest month | Years |
|---|---|---|---|---|---|
| January | 15.0°C5 Jan 1997 | -36.1°C30 Jan 1951 | 34 mm23 Jan 2018 | 88 mm1999 · driest 2 mm in 2025 | 86 |
| February | 22.2°C28 Feb 2024 | -33.9°C3 Feb 1996 | 36 mm21 Feb 1997 | 92 mm2023 · driest 2 mm in 1969 | 86 |
| March | 28.3°C22 Mar 2012 | -28.3°C1 Mar 1962 | 64 mm31 Mar 1998 | 125 mm2024 · driest 8 mm in 1968 | 86 |
| April | 31.1°C19 Apr 2002 | -15.6°C6 Apr 1982 | 60 mm23 Apr 1999 | 194 mm2026 · driest 16 mm in 1895 | 86 |
| May | 34.4°C20 May 1975 | -5.0°C10 May 1966 | 72 mm13 May 2014 | 264 mm2004 · driest 13 mm in 2026 | 86 |
| June | 37.8°C20 Jun 1988 | -0.6°C4 Jun 1945 | 90 mm8 Jun 2008 | 294 mm2008 · driest 9 mm in 2012 | 85 |
| July | 39.4°C6 Jul 2012 | 5.0°C17 Jul 1896 | 122 mm18 Jul 1952 | 248 mm2010 · driest 20 mm in 1944 | 85 |
| August | 38.3°C17 Aug 1988 | 3.9°C6 Aug 1893 | 137 mm10 Aug 1995 | 289 mm1995 · driest 8 mm in 1955 | 85 |
| September | 36.7°C1 Sep 1953 | -3.3°C29 Sep 1949 | 127 mm12 Sep 2022 | 278 mm1986 · driest 7 mm in 2004 | 85 |
| October | 30.6°C4 Oct 2005 | -12.2°C30 Oct 1895 | 72 mm31 Oct 1984 | 191 mm1984 · driest 3 mm in 1952 | 84 |
| November | 24.4°C4 Nov 2015 | -25.6°C30 Nov 1947 | 61 mm6 Nov 2005 | 153 mm1985 · driest 9 mm in 2007 | 85 |
| December | 19.4°C6 Dec 2001 | -31.7°C23 Dec 1983 | 42 mm15 Dec 1971 | 126 mm2015 · driest 3 mm in 1960 | 85 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 29 | 1 | 9 |
| February | 0 | 0 | 26 | 1 | 7 |
| March | <1 | 0 | 23 | 2 | 4 |
| April | 1 | <1 | 10 | 3 | 2 |
| May | 7 | 1 | 1 | 4 | 0 |
| June | 18 | 5 | 0 | 4 | 0 |
| July | 25 | 8 | 0 | 3 | 0 |
| August | 23 | 5 | 0 | 3 | 0 |
| September | 12 | 2 | <1 | 3 | 0 |
| October | 2 | <1 | 7 | 2 | <1 |
| November | 0 | 0 | 19 | 2 | 2 |
| December | 0 | 0 | 28 | 1 | 8 |
The best month has moved. On the 1961–1990 numbers the strongest month here was June (scoring 82); on 2011–2025 it is September (86). 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 | 0% | 20% | 3% | 17% | -6.4–0.7°C |
| February | <1% | 19% | 3% | 17% | -4.1–3.7°C |
| March | 3% | 23% | 5% | 24% | 2.4–9.7°C |
| April | 15% | 30% | 9% | 36% | 10.7–16.8°C |
| May | 41% | 31% | 10% | 36% | 17.9–23.4°C |
| June | 65% | 30% | 12% | 34% | 23.9–27.7°C |
| July | 75% | 24% | 10% | 23% | 26.4–30.3°C |
| August | 73% | 26% | 11% | 26% | 25.2–29.1°C |
| September | 57% | 25% | 9% | 28% | 20.8–25.1°C |
| October | 22% | 23% | 7% | 26% | 13.1–19.0°C |
| November | 2% | 23% | 6% | 21% | 4.0–10.2°C |
| December | 0% | 21% | 4% | 20% | -3.2–3.5°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 5250393
- NOAA station
- USC00476200 · OCONOMOWOC WWTP
- Station distance
- 9.2 km from the place centre
- Climate period
- 1991–2020
- Minimum month coverage
- 29 usable years
- Daylight
- Calculated from latitude 43.06°, mid-month, sunrise to sunset including refraction. Not a station measurement.
- Sea temperature
- NOAA OISST v2.1 1991–2020 monthly climatology, nearest open water 44 km from the place centre. A sheltered bay can run warmer than the open sea it is measured from.
- Important limit
- Historical climate is not a forecast. Nearby stations can miss mountains, coasts, and local microclimates.