September
September · August · June
74climate match
United States · 1991–2020
Best time to visit
Dayton.
September leads for comfortable weather in Dayton: typically 23.5°C by day, 9.5°C at night, with 103 mm of rain. Based on measured 1991–2020 NOAA station history.
Best comfortSeptember
Typical high23.5°C
Typical low9.5°C
Rain in September103 mm
July
July · August · June
55climate match
September
September · May · October
70climate match
The weakest month is January, scoring 5 against September’s 74 — days reach only 1.6°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
51.6° / -8.3°
Feb
53° / -8.3°
Mar
58.1° / -4.3°
Apr
3215.9° / 1.2°
May
6021.4° / 7.1°
Jun
7025.6° / 12.1°
Jul
6927.7° / 14.2°
Aug
7227.1° / 13.7°
Sep
7423.5° / 9.5°
Oct
4316.8° / 3.7°
Nov
99.8° / -1.2°
Dec
54° / -5.1°
| Month | Day | Night | Rain | Wet days | Daylight | Comfort | Coverage |
|---|---|---|---|---|---|---|---|
| January | 1.6°C | -8.3°C | 91 mm | 11.4 | 9 h 32 | 5 | Strong coverage |
| February | 3°C | -8.3°C | 71 mm | 9.1 | 10 h 34 | 5 | Strong coverage |
| March | 8.1°C | -4.3°C | 92 mm | 11 | 11 h 49 | 5 | Strong coverage |
| April | 15.9°C | 1.2°C | 100 mm | 11.6 | 13 h 14 | 32 | Strong coverage |
| May | 21.4°C | 7.1°C | 104 mm | 11.3 | 14 h 26 | 60 | Strong coverage |
| June | 25.6°C | 12.1°C | 125 mm | 10.7 | 15 h 05 | 70 | Strong coverage |
| July | 27.7°C | 14.2°C | 118 mm | 9.9 | 14 h 50 | 69 | Strong coverage |
| August | 27.1°C | 13.7°C | 106 mm | 9.2 | 13 h 48 | 72 | Strong coverage |
| September | 23.5°C | 9.5°C | 103 mm | 8.3 | 12 h 25 | 74 | Strong coverage |
| October | 16.8°C | 3.7°C | 88 mm | 9.6 | 11 h 02 | 43 | Strong coverage |
| November | 9.8°C | -1.2°C | 95 mm | 10.2 | 9 h 50 | 9 | Strong coverage |
| December | 4°C | -5.1°C | 90 mm | 10.6 | 9 h 15 | 5 | Strong coverage |
What has changed
Dayton runs +0.8°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
+0.8
Feb
+1.5
Mar
+1.2
Apr
+1.2
May
+0.8
Jun
0.0
Jul
+0.4
Aug
+0.1
Sep
+1.0
Oct
+0.9
Nov
0.0
Dec
+2.0
| Month | Record high | Record low | Wettest day | Wettest / driest month | Years |
|---|---|---|---|---|---|
| January | 22.8°C26 Jan 1950 | -30.0°C20 Jan 1994 | 89 mm17 Jan 2005 | 266 mm2005 · driest 18 mm in 2016 | 82 |
| February | 22.8°C25 Feb 2017 | -30.0°C25 Feb 2015 | 48 mm14 Feb 1966 | 187 mm2018 · driest 10 mm in 2006 | 82 |
| March | 28.9°C31 Mar 1998 | -24.4°C9 Mar 1960 | 52 mm10 Mar 1964 | 192 mm1994 · driest 22 mm in 1969 | 80 |
| April | 32.2°C24 Apr 1985 | -11.7°C2 Apr 1949 | 66 mm28 Apr 1948 | 250 mm1948 · driest 12 mm in 2013 | 83 |
| May | 33.3°C26 May 1951 | -8.3°C10 May 1947 | 61 mm29 May 2017 | 212 mm1953 · driest 25 mm in 2013 | 83 |
| June | 37.8°C27 Jun 1948 | -2.2°C4 Jun 2019 | 99 mm12 Jun 1986 | 299 mm2015 · driest 26 mm in 1991 | 82 |
| July | 39.4°C17 Jul 1988 | 2.2°C9 Jul 1963 | 102 mm13 Jul 2004 | 299 mm1990 · driest 35 mm in 1989 | 83 |
| August | 37.2°C18 Aug 1988 | 0.6°C29 Aug 1982 | 82 mm15 Aug 1980 | 224 mm1980 · driest 15 mm in 2025 | 83 |
| September | 35.6°C4 Sep 1953 | -5.6°C27 Sep 1957 | 146 mm30 Sep 2015 | 225 mm2004 · driest 3 mm in 2007 | 82 |
| October | 31.1°C2 Oct 2019 | -9.4°C31 Oct 1988 | 123 mm16 Oct 1954 | 222 mm1954 · driest 1 mm in 1963 | 83 |
| November | 26.7°C3 Nov 1982 | -18.9°C30 Nov 1958 | 71 mm8 Nov 1997 | 256 mm1985 · driest 18 mm in 1976 | 83 |
| December | 22.8°C4 Dec 1982 | -28.3°C18 Dec 1951 | 65 mm1 Dec 2010 | 189 mm1990 · driest 10 mm in 1955 | 82 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 26 | 3 | 6 |
| February | 0 | 0 | 24 | 2 | 4 |
| March | <1 | 0 | 23 | 3 | 3 |
| April | 3 | <1 | 13 | 4 | <1 |
| May | 9 | 1 | 3 | 4 | 0 |
| June | 17 | 5 | <1 | 4 | 0 |
| July | 24 | 8 | 0 | 4 | 0 |
| August | 23 | 7 | 0 | 3 | 0 |
| September | 12 | 2 | <1 | 3 | 0 |
| October | 3 | <1 | 8 | 3 | 0 |
| November | 0 | 0 | 18 | 3 | 1 |
| December | 0 | 0 | 26 | 3 | 3 |
| Month | Warm & dry days | Wet days | Washouts | Week with 3+ wet days | Daytime mean has ranged |
|---|---|---|---|---|---|
| January | 0% | 36% | 8% | 49% | -1.9–5.0°C |
| February | <1% | 34% | 8% | 44% | -0.7–6.3°C |
| March | 5% | 36% | 10% | 51% | 4.7–12.1°C |
| April | 19% | 39% | 12% | 54% | 12.9–18.0°C |
| May | 42% | 38% | 13% | 52% | 18.8–24.2°C |
| June | 61% | 35% | 14% | 46% | 24.0–27.4°C |
| July | 67% | 32% | 13% | 38% | 26.2–29.8°C |
| August | 69% | 30% | 11% | 34% | 25.3–28.9°C |
| September | 57% | 29% | 10% | 34% | 21.5–25.4°C |
| October | 26% | 30% | 10% | 36% | 14.6–19.5°C |
| November | 4% | 35% | 10% | 48% | 6.6–12.7°C |
| December | <1% | 35% | 9% | 50% | 0.0–7.1°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 5186474
- NOAA station
- USC00367229 · PUTNEYVILLE 2 SE DAM
- Station distance
- 6 km from the place centre
- Climate period
- 1991–2020
- Minimum month coverage
- 28 usable years
- Daylight
- Calculated from latitude 40.88°, 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.