Boston, MA

Massachusetts · Records since 1872–2026

☁️ 62°F Feels like 56°
Currently in Boston
As of 10:00 PM EDT

Records for September 26

🔥 Record High

95°F

September 26, 1881

+26° from 69° normal

❄ Record Low

34°F

September 26, 1879

-21° from 55° normal
🌞 Normal high: 69°F 🌑 Normal low: 55°F 1991–2020 normals

All-Time Records — Boston

🔥
104°F
Hottest Day Ever
Jul 4, 1911
❄
-18°F
Coldest Day Ever
Feb 9, 1934
🌧
7.06"
Wettest Day Ever
Aug 19, 1955
☃
23.6"
Most Snow in One Day
Jan 29, 2022

First & Last Dates — Boston

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)
254 days
Longest growing season
2009
162 days
Shortest growing season
1883
220 days
Normal growing season
1991–2020 average

Top 10 Record Highs — September 26

# Temp Date
🏆 95°F September 26, 1881
2 93°F September 26, 2007
3 89°F September 26, 1958
4 87°F September 26, 1961
5 85°F September 26, 1895
6 84°F September 26, 2019
7 84°F September 26, 2018
8 84°F September 26, 1920
9 83°F September 26, 1972
10 82°F September 26, 2025

Top 5 Record Lows — September 26

# Temp Date
🥶 34°F September 26, 1879
2 41°F September 26, 1936
3 41°F September 26, 1925
4 42°F September 26, 1978
5 42°F September 26, 1947
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 1872–2026. Climate normals represent the 1991–2020 average.

Heat Wave Summary — Boston

threshold: 90°F (90th percentile of historical Jun–Aug highs)
3.8
Avg heat wave length
days (historical)
96°
Avg peak temp
during heat waves
21
Dangerous nights 2026
Overnights ≥ 70°F
2
Heat waves 2026
so far

Days ≥ 90°F Per Year

1872–2026
16
2026 so far
12
Avg/year 1970–2025
17
Avg/year (last 10 complete)
30
Most in a year (1983)

Average Daily High by Decade

Full year · complete decades only

Longest Heat Waves — Boston

# Dates Days Peak Avg High Avg Overnight Low
🏆 Jul 3, 1912 – Jul 11, 1912 9 99°F (Jul 9) 93°F 70°F
2 Aug 10, 1944 – Aug 17, 1944 8 101°F (Aug 12) 97°F 73°F
3 Aug 11, 2002 – Aug 18, 2002 8 101°F (Aug 14) 95°F 74°F
4 Jun 28, 1872 – Jul 5, 1872 8 98°F (Jul 1) 94°F 70°F
5 Jul 19, 1994 – Jul 26, 1994 8 97°F (Jul 21) 92°F 72°F
6 Jul 19, 2022 – Jul 25, 2022 7 100°F (Jul 24) 94°F 74°F
7 Jul 15, 1983 – Jul 21, 1983 7 99°F (Jul 16) 94°F 72°F
8 Jul 14, 2013 – Jul 20, 2013 7 99°F (Jul 19) 94°F 75°F
9 Jun 27, 1901 – Jul 3, 1901 7 97°F (Jun 28) 94°F 73°F
10 Aug 9, 1988 – Aug 15, 1988 7 96°F (Aug 15) 93°F 73°F

Heat Waves Per Year

Warm Summer Nights (Jun–Aug)

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

62
2026 total
above-normal nights
40.3
Avg / summer
1970–2020
61
Most in a summer
1983

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 (1872–2026)

Blue = above average · tan = below average · gold = 2026 (partial)
Since 1872, annual totals have trended +0.10" per decade, about +1.6" 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 Boston is tracking against normal, year to date

Daily High Temperature vs Normal

Above normal Below normal

123 of 267 days with data were above the 1991–2020 normal high for their date.

Precipitation, Year to Date

19.37"
2026 YTD
Normal: 30.83"
-11.46"
1.81"
September so far
September normal: 3.56"
-1.75"
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 · Boston is 11.46" behind the normal pace

Period Review — Sep 18 – Sep 25, 2026

Any window, evaluated against every other year on record — 8 days

Quick picks: Last 7 days Last 30 days Last 90 days This month
Seasons: Spring (Mar–May) Summer (Jun–Aug) Fall (Sep–Nov)
60.1°F
Average temperature
46th-coolest of 155
-3.7°
vs. average
Normal: 63.8°F (1991–2020)

Average Temperature by Year — Sep 18 – Sep 25

1872–2026 · 2026 highlighted · trend +0.19° per decade (warming since 1872)

Precipitation by Year — Sep 18 – Sep 25

1872–2025 · 2026 highlighted

Warmest Sep 18 – Sep 25 on Record

# Year Avg Temp
1 1914 72.6°F
2 1970 70.6°F
3 1946 70.1°F
4 1965 69.9°F
5 1930 69.8°F
6 2021 69.8°F
7 1891 69.3°F
8 1895 69.2°F
9 1983 69.2°F
10 2019 68.9°F

Coolest Sep 18 – Sep 25 on Record

# Year Avg Temp
1 1875 51.1°F
2 1888 55.1°F
3 1956 55.4°F
4 1929 55.8°F
5 1969 56.4°F
6 1962 56.9°F
7 1876 57.0°F
8 1950 57.1°F
9 1887 57.2°F
10 1886 57.3°F
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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