September
September · August · June
73climate match
United States · 1991–2020
Best time to visit
Mountain Valley Trailer Court.
September leads for comfortable weather in Mountain Valley Trailer Court: typically 22.5°C by day, 3.4°C at night, with 25 mm of rain. Based on measured 1991–2020 NOAA station history.
Best comfortSeptember
Typical high22.5°C
Typical low3.4°C
Rain in September25 mm
July
July · August · June
61climate match
September
September · June · May
79climate match
The weakest month is January, scoring 5 against September’s 73 — days reach only 2°C, 22° below the 24°C the score treats as ideal, and nights drop to -11°C.
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° / -11°
Feb
53.8° / -9.6°
Mar
128.7° / -5.9°
Apr
3012.8° / -2.7°
May
5017.9° / 1.9°
Jun
7122.7° / 6°
Jul
7128.4° / 9.2°
Aug
7228.1° / 7.9°
Sep
7322.5° / 3.4°
Oct
3614.4° / -2.2°
Nov
56° / -7.4°
Dec
51.1° / -11.3°
| Month | Day | Night | Rain | Wet days | Daylight | Comfort | Coverage |
|---|---|---|---|---|---|---|---|
| January | 2°C | -11°C | 7 mm | 2.4 | 8 h 59 | 5 | Strong coverage |
| February | 3.8°C | -9.6°C | 8 mm | 2.4 | 10 h 15 | 5 | Strong coverage |
| March | 8.7°C | -5.9°C | 10 mm | 3.4 | 11 h 45 | 12 | Strong coverage |
| April | 12.8°C | -2.7°C | 18 mm | 4.6 | 13 h 29 | 30 | Strong coverage |
| May | 17.9°C | 1.9°C | 45 mm | 8.7 | 14 h 57 | 50 | Strong coverage |
| June | 22.7°C | 6°C | 55 mm | 8.8 | 15 h 46 | 71 | Strong coverage |
| July | 28.4°C | 9.2°C | 41 mm | 6.4 | 15 h 26 | 71 | Strong coverage |
| August | 28.1°C | 7.9°C | 28 mm | 5.2 | 14 h 10 | 72 | Strong coverage |
| September | 22.5°C | 3.4°C | 25 mm | 4.6 | 12 h 29 | 73 | Strong coverage |
| October | 14.4°C | -2.2°C | 19 mm | 4.5 | 10 h 49 | 36 | Strong coverage |
| November | 6°C | -7.4°C | 14 mm | 3.4 | 9 h 22 | 5 | Strong coverage |
| December | 1.1°C | -11.3°C | 9 mm | 2.7 | 8 h 38 | 5 | Strong coverage |
What has changed
Mountain Valley Trailer Court runs +0.7°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
+1.3
Feb
-1.4
Mar
+1.8
Apr
+0.1
May
-0.1
Jun
+1.1
Jul
+1.3
Aug
+0.8
Sep
+2.2
Oct
-0.9
Nov
+1.0
Dec
+0.7
| Month | Record high | Record low | Wettest day | Wettest / driest month | Years |
|---|---|---|---|---|---|
| January | 14.4°C19 Jan 2005 | -38.9°C26 Jan 1957 | 15 mm26 Jan 1975 | 45 mm1969 · driest 1 mm in 2001 | 75 |
| February | 18.3°C20 Feb 1995 | -39.4°C3 Feb 1989 | 15 mm17 Feb 1986 | 31 mm1949 · driest 0 mm in 1977 | 74 |
| March | 23.3°C22 Mar 2026 | -30.6°C8 Mar 1951 | 13 mm16 Mar 1965 | 34 mm2014 · driest 1 mm in 1959 | 76 |
| April | 28.3°C28 Apr 1987 | -21.1°C6 Apr 1997 | 35 mm26 Apr 1955 | 58 mm1975 · driest 1 mm in 2021 | 77 |
| May | 31.7°C19 May 1954 | -12.8°C9 May 1996 | 43 mm24 May 1981 | 143 mm1981 · driest 4 mm in 2021 | 75 |
| June | 35.6°C15 Jun 2021 | -5.6°C1 Jun 1954 | 39 mm10 Jun 2006 | 113 mm1963 · driest 2 mm in 2021 | 74 |
| July | 38.3°C14 Jul 2002 | -1.7°C20 Jul 1993 | 47 mm10 Jul 1983 | 99 mm1993 · driest 1 mm in 2024 | 77 |
| August | 37.8°C5 Aug 1961 | -7.2°C25 Aug 1992 | 39 mm7 Aug 2023 | 125 mm1990 · driest 0 mm in 2017 | 77 |
| September | 35.6°C6 Sep 2022 | -13.3°C17 Sep 1965 | 30 mm8 Sep 1995 | 71 mm1965 · driest 1 mm in 2021 | 77 |
| October | 30.6°C2 Oct 1992 | -25.6°C30 Oct 1991 | 19 mm3 Oct 1967 | 60 mm1975 · driest 0 mm in 2024 | 75 |
| November | 21.7°C12 Nov 1999 | -36.7°C16 Nov 1959 | 27 mm29 Nov 1971 | 42 mm1973 · driest 1 mm in 2004 | 76 |
| December | 18.3°C2 Dec 2021 | -41.1°C22 Dec 1990 | 16 mm3 Dec 1948 | 35 mm1977 · driest 0 mm in 1997 | 75 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 29 | 0 | 3 |
| February | 0 | 0 | 26 | 0 | 3 |
| March | 0 | 0 | 27 | <1 | 2 |
| April | <1 | 0 | 22 | <1 | 1 |
| May | 4 | <1 | 9 | 1 | <1 |
| June | 11 | 2 | 2 | 1 | 0 |
| July | 25 | 13 | <1 | 1 | 0 |
| August | 25 | 12 | <1 | <1 | 0 |
| September | 11 | 2 | 6 | <1 | <1 |
| October | 1 | 0 | 20 | <1 | <1 |
| November | 0 | 0 | 25 | <1 | 2 |
| December | 0 | 0 | 29 | 0 | 4 |
| Month | Warm & dry days | Wet days | Washouts | Week with 3+ wet days | Daytime mean has ranged |
|---|---|---|---|---|---|
| January | 0% | 11% | <1% | 6% | -2.5–4.7°C |
| February | 0% | 10% | <1% | 5% | -0.5–7.3°C |
| March | 1% | 12% | <1% | 7% | 3.5–11.5°C |
| April | 13% | 15% | 1% | 10% | 10.2–16.3°C |
| May | 34% | 27% | 4% | 34% | 15.5–20.5°C |
| June | 57% | 29% | 5% | 36% | 20.2–25.5°C |
| July | 79% | 20% | 3% | 16% | 25.8–31.0°C |
| August | 80% | 18% | 2% | 17% | 25.3–30.4°C |
| September | 62% | 17% | 3% | 14% | 19.1–25.6°C |
| October | 26% | 12% | 1% | 6% | 12.5–18.0°C |
| November | <1% | 11% | <1% | 7% | 3.4–9.2°C |
| December | 0% | 11% | <1% | 6% | -2.0–4.7°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 5667506
- NOAA station
- USC00241008 · BOULDER
- Station distance
- 1 km from the place centre
- Climate period
- 1991–2020
- Minimum month coverage
- 28 usable years
- Daylight
- Calculated from latitude 46.23°, 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.