Missoula, MT

Montana · Records since 1893–2026

⛅ 64°F
Currently in Missoula
As of 12:30 PM MDT

Records for September 11

🔥 Record High

92°F

September 11, 1959

+17° from 75° normal

❄ Record Low

30°F

September 11, 1964

-14° from 44° normal
🌞 Normal high: 75°F 🌑 Normal low: 44°F 1991–2020 normals

All-Time Records — Missoula

🔥
107°F
Hottest Day Ever
Jul 6, 2007
❄
-33°F
Coldest Day Ever
Jan 26, 1957
🌧
2.32"
Wettest Day Ever
Nov 5, 1927
☃
19.7"
Most Snow in One Day
Feb 12, 1936

First & Last Dates — Missoula

How early and how late each seasonal turning point has ever arrived, across the full period of record

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Range ever recorded Normal date (1991–2020)
179 days
Longest growing season
1938
6 days
Shortest growing season
1901
130 days
Normal growing season
1991–2020 average

Top 10 Record Highs — September 11

# Temp Date
🏆 92°F September 11, 1959
2 91°F September 11, 1990
3 91°F September 11, 1940
4 91°F September 11, 1937
5 90°F September 11, 2013
6 90°F September 11, 1958
7 90°F September 11, 1953
8 89°F September 11, 1963
9 89°F September 11, 1944
10 88°F September 11, 1908

Top 5 Record Lows — September 11

# Temp Date
🥶 30°F September 11, 1964
2 31°F September 11, 2014
3 31°F September 11, 1989
4 32°F September 11, 1913
5 32°F September 11, 1895
About this data — Records are sourced from the NOAA Threadex dataset via RCC ACIS, a quality-controlled record for long-term climate stations. Threadex adjusts for station relocations and observation-time changes, making records comparable across all years since 1893–2026. Climate normals represent the 1991–2020 average.

Heat Wave Summary — Missoula

threshold: 94°F (90th percentile of historical Jun–Aug highs)
4.4
Avg heat wave length
days (historical)
99°
Avg peak temp
during heat waves
0
Dangerous nights 2026
Overnights ≥ 70°F
1
Heat waves 2026
so far

Days ≥ 90°F Per Year

1893–2026
30
2026 so far
23
Avg/year 1970–2025
34
Avg/year (last 10 complete)
53
Most in a year (2007)

Average Daily High by Decade

Full year · complete decades only

Longest Heat Waves — Missoula

# Dates Days Peak Avg High Avg Overnight Low
🏆 Jul 8, 2024 – Jul 24, 2024 17 102°F (Jul 24) 98°F 57°F
2 Jul 11, 1960 – Jul 22, 1960 12 105°F (Jul 19) 99°F 53°F
3 Aug 10, 1967 – Aug 20, 1967 11 99°F (Aug 17) 97°F 51°F
4 Jun 27, 2021 – Jul 6, 2021 10 102°F (Jun 30) 98°F 57°F
5 Jul 15, 2003 – Jul 23, 2003 9 103°F (Jul 23) 99°F 56°F
6 Jul 21, 2006 – Jul 29, 2006 9 102°F (Jul 22) 98°F 59°F
7 Jun 26, 2015 – Jul 4, 2015 9 102°F (Jun 28) 97°F 60°F
8 Jul 21, 1994 – Jul 29, 1994 9 101°F (Jul 26) 99°F 58°F
9 Jul 16, 1936 – Jul 23, 1936 8 105°F (Jul 22) 101°F 62°F
10 Jul 11, 2007 – Jul 18, 2007 8 103°F (Jul 14) 100°F 60°F

Heat Waves Per Year

Warm Summer Nights (Jun–Aug)

Nights where the overnight low exceeded the 1991–2020 normal low

52
2026 total
above-normal nights
41.2
Avg / summer
1970–2020
73
Most in a summer
1936

Above-Normal Summer Nights Per Year

Average June–August Low by Decade

Overnight lows · complete decades only

Precipitation

Annual totals and trend across the full period of record · see this year's standing →

Monthly Precipitation — Last 24 Months

Blue = actual · dashed line = monthly normal

Annual Precipitation Per Year (1893–2026)

Blue = above average · tan = below average · gold = 2026 (partial)

Heavy Rain Days Per Year (≥ 1.0")

Compare year-to-year changes in days with heavy rainfall (≥ 1.0")

This Year — 2026

How Missoula is tracking against normal, year to date

Daily High Temperature vs Normal

Above normal Below normal

169 of 253 days with data were above the 1991–2020 normal high for their date.

Precipitation, Year to Date

11.50"
2026 YTD
Normal: 10.04"
+1.46"
1.87"
September so far
September normal: 0.96"
+0.91"
1
2026 heavy rain days
Days with ≥ 1.0"

Accumulation vs. Normal

Running total since Jan 1 against the normal pace for the same date · Missoula is 1.46" ahead of the normal pace

Period Review — Aug 11 – Sep 10, 2026

Any window, evaluated against every other year on record — 31 days

Quick picks: Last 7 days Last 30 days Last 90 days This month
Seasons: Spring (Mar–May) Summer (Jun–Aug) Fall (Sep–Nov)
65.3°F
Average temperature
41st-warmest of 124
+0.5°
vs. average
Normal: 64.8°F (1991–2020)
2.42"
Precipitation
11th-wettest of 112
+1.45"
vs. average
Normal: 0.97" · 249% of normal

Average Temperature by Year — Aug 11 – Sep 10

1893–2026 · 2026 highlighted · trend +0.21° per decade (warming since 1893)

Precipitation by Year — Aug 11 – Sep 10

1893–2026 · 2026 highlighted · trend -0.01" per decade (drier since 1893)

Warmest Aug 11 – Sep 10 on Record

# Year Avg Temp
1 2022 71.9°F
2 2013 70.7°F
3 1967 70.4°F
4 2025 70.3°F
5 1940 70.0°F
6 2023 68.8°F
7 1904 68.2°F
8 2017 68.1°F
9 1923 67.7°F
10 1998 67.7°F

Coolest Aug 11 – Sep 10 on Record

# Year Avg Temp
1 1964 57.0°F
2 1910 58.0°F
3 1912 58.0°F
4 1899 58.1°F
5 1989 58.9°F
6 1959 59.0°F
7 1965 59.0°F
8 1954 59.1°F
9 1895 59.1°F
10 1960 59.3°F

Wettest Aug 11 – Sep 10 on Record

# Year Total
1 1985 3.60"
2 1897 3.13"
3 2004 2.96"
4 1986 2.93"
5 1926 2.91"
6 1995 2.73"
7 1968 2.72"
8 1990 2.68"
9 2019 2.68"
10 2023 2.62"

Driest Aug 11 – Sep 10 on Record

# Year Total
1 1917 0.00"
2 1902 0.00"
3 1929 0.02"
4 1969 0.04"
5 1967 0.04"
6 1955 0.07"
7 1948 0.09"
8 2022 0.11"
9 2012 0.11"
10 1950 0.13"
About this data. Pick any start and end date and this becomes the same kind of review as the Month and Fall tabs, just for exactly the window you asked for — the generalized version of the same engine, evaluated across every year on record. Average temperature is the mean of each day's (high + low) / 2; precipitation is the sum of daily totals. A year missing more than about a fifth of the window's days is excluded from the temperature ranking; any missing day excludes a year from the precipitation ranking, since an unreported day is unreported rain. Ranges that cross from December into January aren't supported yet. Normals are the 1991–2020 mean for the same window.
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