Islip, NY

New York · Records since 1963–2026

☀️ 78°F
Currently in Islip
As of 2:30 PM EDT

Records for September 11

🔥 Record High

92°F

September 11, 1983

+16° from 76° normal

❄ Record Low

45°F

September 11, 1969

-16° from 61° normal
🌞 Normal high: 76°F 🌑 Normal low: 61°F 1991–2020 normals

All-Time Records — Islip

🔥
104°F
Hottest Day Ever
Jul 3, 1966
❄
-14°F
Coldest Day Ever
Feb 13, 1967
🌧
13.51"
Wettest Day Ever
Aug 13, 2014
☃
23.5"
Most Snow in One Day
Jan 29, 2022

First & Last Dates — Islip

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)
230 days
Longest growing season
2024
159 days
Shortest growing season
1968
199 days
Normal growing season
1991–2020 average

Top 10 Record Highs — September 11

# Temp Date
🏆 92°F September 11, 1983
2 88°F September 11, 2013
3 88°F September 11, 1989
4 87°F September 11, 1982
5 86°F September 11, 1990
6 83°F September 11, 2016
7 82°F September 11, 2018
8 82°F September 11, 1981
9 82°F September 11, 1964
10 81°F September 11, 2025

Top 5 Record Lows — September 11

# Temp Date
🥶 45°F September 11, 1969
2 46°F September 11, 1975
3 47°F September 11, 1995
4 49°F September 11, 1994
5 50°F September 11, 1993
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 1963–2026. Climate normals represent the 1991–2020 average.

Heat Wave Summary — Islip

threshold: 88°F (90th percentile of historical Jun–Aug highs)
4.0
Avg heat wave length
days (historical)
94°
Avg peak temp
during heat waves
24
Dangerous nights 2026
Overnights ≥ 70°F
2
Heat waves 2026
so far

Days ≥ 90°F Per Year

1964–2026
9
2026 so far
7
Avg/year 1970–2025
9
Avg/year (last 10 complete)
18
Most in a year (1999)

Average Daily High by Decade

Full year · complete decades only

Longest Heat Waves — Islip

# Dates Days Peak Avg High Avg Overnight Low
🏆 Jul 29, 2006 – Aug 5, 2006 8 98°F (Aug 2) 93°F 74°F
2 Aug 28, 1973 – Sep 4, 1973 8 96°F (Aug 30) 92°F 70°F
3 Aug 2, 1980 – Aug 9, 1980 8 94°F (Aug 9) 90°F 74°F
4 Jul 18, 1991 – Jul 24, 1991 7 101°F (Jul 21) 93°F 73°F
5 Jul 7, 1993 – Jul 13, 1993 7 98°F (Jul 10) 93°F 72°F
6 Jul 12, 1997 – Jul 18, 1997 7 96°F (Jul 15) 92°F 69°F
7 Jul 14, 2013 – Jul 20, 2013 7 95°F (Jul 18) 93°F 76°F
8 Jul 3, 1999 – Jul 8, 1999 6 102°F (Jul 5) 95°F 74°F
9 Aug 11, 2016 – Aug 16, 2016 6 97°F (Aug 14) 92°F 76°F
10 Jul 16, 1977 – Jul 21, 1977 6 96°F (Jul 20) 92°F 72°F

Heat Waves Per Year

Warm Summer Nights (Jun–Aug)

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

45
2026 total
above-normal nights
40.1
Avg / summer
1970–2020
61
Most in a summer
2020

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 (1963–2026)

Blue = above average · tan = below average · gold = 2026 (partial)
Since 1963, annual totals have trended +1.35" per decade, about +8.4" 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 Islip is tracking against normal, year to date

Daily High Temperature vs Normal

Above normal Below normal

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

Precipitation, Year to Date

32.78"
2026 YTD
Normal: 31.43"
+1.35"
1.15"
September so far
September normal: 3.60"
-2.45"
10
2026 heavy rain days
Days with ≥ 1.0"

Accumulation vs. Normal

Running total since Jan 1 against the normal pace for the same date · Islip is 1.35" ahead of the normal pace

Period Review — Mar 1 – May 31, 2026

Any window, evaluated against every other year on record — 92 days

Quick picks: Last 7 days Last 30 days Last 90 days This month
Seasons: Spring (Mar–May) Summer (Jun–Aug) Fall (Sep–Nov)
50.8°F
Average temperature
14th-warmest of 63
+1.2°
vs. average
Normal: 49.7°F (1991–2020)
9.02"
Precipitation
13th-driest of 61
-2.86"
vs. average
Normal: 11.88" · 76% of normal

Average Temperature by Year — Mar 1 – May 31

1964–2026 · 2026 highlighted · trend +0.56° per decade (warming since 1964)

Precipitation by Year — Mar 1 – May 31

1964–2026 · 2026 highlighted · trend +0.11" per decade (wetter since 1964)

Warmest Mar 1 – May 31 on Record

# Year Avg Temp
1 2012 54.1°F
2 2010 53.6°F
3 2025 53.1°F
4 1991 52.9°F
5 2024 52.5°F
6 2022 51.4°F
7 2023 51.4°F
8 1977 51.4°F
9 2016 51.3°F
10 1998 51.2°F

Coolest Mar 1 – May 31 on Record

# Year Avg Temp
1 1967 43.3°F
2 1968 46.5°F
3 2005 46.5°F
4 1978 46.5°F
5 1984 46.6°F
6 1992 46.7°F
7 1965 46.8°F
8 1966 47.0°F
9 1972 47.0°F
10 2003 47.3°F

Wettest Mar 1 – May 31 on Record

# Year Total
1 1998 22.91"
2 1984 19.77"
3 1983 19.65"
4 1989 19.60"
5 2024 17.66"
6 1990 16.55"
7 2018 15.52"
8 2010 15.04"
9 1980 15.00"
10 1973 14.99"

Driest Mar 1 – May 31 on Record

# Year Total
1 1995 6.00"
2 1986 6.49"
3 1976 6.85"
4 1981 6.95"
5 2015 7.15"
6 2013 7.22"
7 1969 8.24"
8 1985 8.30"
9 1992 8.45"
10 2012 8.60"
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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