Seattle Tacoma, WA

Washington · Records since 1945–2026

☁️ 63°F
Currently in Seattle Tacoma
As of 11:30 AM PDT

Records for September 11

🔥 Record High

93°F

September 11, 2013

+20° from 73° normal

❄ Record Low

40°F

September 11, 1952

-14° from 54° normal
🌞 Normal high: 73°F 🌑 Normal low: 54°F 1991–2020 normals

All-Time Records — Seattle Tacoma

🔥
108°F
Hottest Day Ever
Jun 28, 2021
❄
0°F
Coldest Day Ever
Jan 31, 1950
🌧
5.02"
Wettest Day Ever
Oct 20, 2003
☃
20.0"
Most Snow in One Day
Jan 13, 1950

First & Last Dates — Seattle Tacoma

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)
331 days
Longest growing season
2016
176 days
Shortest growing season
1954
254 days
Normal growing season
1991–2020 average

Top 10 Record Highs — September 11

# Temp Date
🏆 93°F September 11, 2013
2 87°F September 11, 2009
3 85°F September 11, 2011
4 84°F September 11, 2007
5 83°F September 11, 1975
6 82°F September 11, 1989
7 82°F September 11, 1960
8 82°F September 11, 1957
9 81°F September 11, 2015
10 81°F September 11, 1969

Top 5 Record Lows — September 11

# Temp Date
🥶 40°F September 11, 1952
2 45°F September 11, 1988
3 45°F September 11, 1972
4 45°F September 11, 1949
5 46°F September 11, 1986
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 1945–2026. Climate normals represent the 1991–2020 average.

Heat Wave Summary — Seattle Tacoma

threshold: 85°F (90th percentile of historical Jun–Aug highs)
3.9
Avg heat wave length
days (historical)
92°
Avg peak temp
during heat waves
0
Dangerous nights 2026
Overnights ≥ 70°F
2
Heat waves 2026
so far

Days ≥ 90°F Per Year

1945–2026
4
2026 so far
4
Avg/year 1970–2025
7
Avg/year (last 10 complete)
13
Most in a year (2022)

Average Daily High by Decade

Full year · complete decades only

Longest Heat Waves — Seattle Tacoma

# Dates Days Peak Avg High Avg Overnight Low
🏆 Aug 12, 1967 – Aug 20, 1967 9 98°F (Aug 16) 89°F 59°F
2 Aug 5, 1977 – Aug 13, 1977 9 96°F (Aug 12) 90°F 59°F
3 Jul 22, 2018 – Jul 30, 2018 9 94°F (Jul 29) 90°F 60°F
4 Aug 6, 1981 – Aug 12, 1981 7 99°F (Aug 9) 92°F 64°F
5 Jul 25, 2022 – Jul 31, 2022 7 95°F (Jul 29) 93°F 63°F
6 Jun 30, 2015 – Jul 6, 2015 7 93°F (Jul 2) 90°F 62°F
7 Jul 25, 2009 – Jul 30, 2009 6 103°F (Jul 29) 94°F 65°F
8 Jul 15, 1979 – Jul 20, 1979 6 98°F (Jul 16) 91°F 59°F
9 Jul 5, 2024 – Jul 10, 2024 6 98°F (Jul 9) 92°F 62°F
10 Jul 23, 1958 – Jul 28, 1958 6 97°F (Jul 28) 90°F 59°F

Heat Waves Per Year

Warm Summer Nights (Jun–Aug)

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

36
2026 total
above-normal nights
27.8
Avg / summer
1970–2020
66
Most in a summer
2015

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 (1945–2026)

Blue = above average · tan = below average · gold = 2026 (partial)
Since 1945, annual totals have trended -0.15" per decade, about -1.2" across the record.

Heavy Rain Days Per Year (≥ 1.0")

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

This Year — 2026

How Seattle Tacoma is tracking against normal, year to date

Daily High Temperature vs Normal

Above normal Below normal

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

Precipitation, Year to Date

20.48"
2026 YTD
Normal: 22.23"
-1.75"
0.35"
September so far
September normal: 1.61"
-1.26"
3
2026 heavy rain days
Days with ≥ 1.0"

Accumulation vs. Normal

Running total since Jan 1 against the normal pace for the same date · Seattle Tacoma is 1.75" behind the normal pace

Period Review — Sep 1 – Sep 10, 2026

Any window, evaluated against every other year on record — 10 days

Quick picks: Last 7 days Last 30 days Last 90 days This month
Seasons: Spring (Mar–May) Summer (Jun–Aug) Fall (Sep–Nov)
62.8°F
Average temperature
41st-warmest of 82
-1.3°
vs. average
Normal: 64.1°F (1991–2020)
0.35"
Precipitation
33rd-wettest of 81
-0.08"
vs. average
Normal: 0.43" · 81% of normal

Average Temperature by Year — Sep 1 – Sep 10

1945–2026 · 2026 highlighted · trend +0.60° per decade (warming since 1945)

Precipitation by Year — Sep 1 – Sep 10

1945–2026 · 2026 highlighted · trend -0.02" per decade (drier since 1945)

Warmest Sep 1 – Sep 10 on Record

# Year Avg Temp
1 2017 71.0°F
2 2020 70.9°F
3 2013 68.5°F
4 2024 67.9°F
5 2011 67.7°F
6 1963 67.5°F
7 2019 67.5°F
8 1993 67.3°F
9 2022 67.3°F
10 1967 67.1°F

Coolest Sep 1 – Sep 10 on Record

# Year Avg Temp
1 2000 57.5°F
2 1952 57.6°F
3 1964 57.9°F
4 1959 58.4°F
5 1970 58.8°F
6 1960 58.8°F
7 1971 58.9°F
8 1985 58.9°F
9 1947 59.3°F
10 1983 59.4°F

Wettest Sep 1 – Sep 10 on Record

# Year Total
1 1978 2.11"
2 1979 2.07"
3 2013 2.03"
4 1945 1.88"
5 1971 1.85"
6 1994 1.51"
7 2009 1.38"
8 1983 1.16"
9 1970 1.13"
10 1985 1.12"

Driest Sep 1 – Sep 10 on Record

# Year Total
1 2024 0.00"
2 2021 0.00"
3 2020 0.00"
4 2017 0.00"
5 2011 0.00"
6 2008 0.00"
7 1998 0.00"
8 1993 0.00"
9 1991 0.00"
10 1987 0.00"
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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