Hillsboro, OR

Oregon · Records since 1929–2026

🌙 57°F Feels like 54°
Currently in Hillsboro
As of 7:15 PM PDT

Records for September 26

🔥 Record High

94°F

September 26, 1991

+21° from 73° normal

❄ Record Low

33°F

September 26, 1961

-12° from 45° normal
🌞 Normal high: 73°F 🌑 Normal low: 45°F 1991–2020 normals

All-Time Records — Hillsboro

🔥
114°F
Hottest Day Ever
Jun 28, 2021
❄
-14°F
Coldest Day Ever
Jan 21, 1930
🌧
3.40"
Wettest Day Ever
Nov 18, 1996
☃
13.5"
Most Snow in One Day
Jan 15, 1930

First & Last Dates — Hillsboro

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)
262 days
Longest growing season
2016
105 days
Shortest growing season
1930
196 days
Normal growing season
1991–2020 average

Top 10 Record Highs — September 26

# Temp Date
🏆 94°F September 26, 1991
2 93°F September 26, 1949
3 91°F September 26, 1967
4 90°F September 26, 2016
5 89°F September 26, 2003
6 87°F September 26, 2022
7 87°F September 26, 1963
8 85°F September 26, 2018
9 85°F September 26, 2006
10 84°F September 26, 1975

Top 5 Record Lows — September 26

# Temp Date
🥶 33°F September 26, 1961
2 33°F September 26, 1945
3 33°F September 26, 1934
4 34°F September 26, 1972
5 35°F September 26, 2000
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 1929–2026. Climate normals represent the 1991–2020 average.

Heat Wave Summary — Hillsboro

threshold: 92°F (90th percentile of historical Jun–Aug highs)
4.0
Avg heat wave length
days (historical)
99°
Avg peak temp
during heat waves
0
Dangerous nights 2026
Overnights ≥ 70°F
0
Heat waves 2026
so far

Days ≥ 90°F Per Year

1930–2026
11
2026 so far
16
Avg/year 1970–2025
24
Avg/year (last 10 complete)
37
Most in a year (1952)

Average Daily High by Decade

Full year · complete decades only

Longest Heat Waves — Hillsboro

# Dates Days Peak Avg High Avg Overnight Low
🏆 Aug 12, 1967 – Aug 20, 1967 9 98°F (Aug 15) 96°F 53°F
2 Jul 26, 2009 – Aug 2, 2009 8 106°F (Jul 29) 99°F 62°F
3 Jul 21, 1939 – Jul 28, 1939 8 103°F (Jul 26) 97°F 56°F
4 Jul 24, 2022 – Jul 31, 2022 8 102°F (Jul 30) 98°F 60°F
5 Jul 4, 2024 – Jul 10, 2024 7 103°F (Jul 9) 98°F 56°F
6 Aug 16, 1950 – Aug 22, 1950 7 98°F (Aug 17) 97°F 55°F
7 Sep 17, 1952 – Sep 23, 1952 7 97°F (Sep 22) 95°F 52°F
8 Jun 30, 2015 – Jul 6, 2015 7 97°F (Jul 1) 95°F 57°F
9 Jul 13, 1941 – Jul 18, 1941 6 104°F (Jul 15) 100°F 62°F
10 Aug 3, 1972 – Aug 8, 1972 6 104°F (Aug 6) 98°F 56°F

Heat Waves Per Year

Warm Summer Nights (Jun–Aug)

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

44
2026 total
above-normal nights
46.3
Avg / summer
1970–2020
79
Most in a summer
1958

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 (1929–2026)

Blue = above average · tan = below average · gold = 2026 (partial)
Since 1929, annual totals have trended -0.11" per decade, about -1.1" 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 Hillsboro is tracking against normal, year to date

Daily High Temperature vs Normal

Above normal Below normal

118 of 237 days with data were above the 1991–2020 normal high for their date.

Precipitation, Year to Date

16.69"
2026 YTD
Normal: 20.73"
-4.04"
0.77"
September so far
September normal: 1.38"
-0.61"
2
2026 heavy rain days
Days with ≥ 1.0"

Accumulation vs. Normal

Running total since Jan 1 against the normal pace for the same date · Hillsboro is 4.04" 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)
60.6°F
Average temperature
45th-warmest of 97
+0.3°
vs. average
Normal: 60.3°F (1991–2020)

Average Temperature by Year — Sep 18 – Sep 25

1930–2026 · 2026 highlighted · trend +0.05° per decade (warming since 1930)

Precipitation by Year — Sep 18 – Sep 25

1930–2025 · 2026 highlighted · trend +0.01" per decade (wetter since 1930)

Warmest Sep 18 – Sep 25 on Record

# Year Avg Temp
1 1952 72.6°F
2 1974 69.5°F
3 1994 68.5°F
4 1991 66.0°F
5 1997 65.8°F
6 2014 65.8°F
7 1967 65.3°F
8 1939 65.1°F
9 1990 65.0°F
10 2011 64.7°F

Coolest Sep 18 – Sep 25 on Record

# Year Avg Temp
1 2007 52.6°F
2 1933 53.5°F
3 1972 54.3°F
4 1934 54.6°F
5 1945 54.6°F
6 1996 55.0°F
7 1988 55.3°F
8 1970 55.4°F
9 2005 55.5°F
10 1986 55.6°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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