Ontario, OR

Oregon · Records since 1945–2026

☀️ 75°F
Currently in Ontario
As of 12:30 PM MDT

Records for September 11

🔥 Record High

99°F

September 11, 1973

+14° from 85° normal

❄ Record Low

34°F

September 11, 2005

-16° from 50° normal
🌞 Normal high: 85°F 🌑 Normal low: 50°F 1991–2020 normals

All-Time Records — Ontario

🔥
113°F
Hottest Day Ever
Jul 12, 1967
❄
-25°F
Coldest Day Ever
Jan 22, 1962
🌧
1.59"
Wettest Day Ever
Sep 14, 1959
☃
10.0"
Most Snow in One Day
Jan 8, 1993

First & Last Dates — Ontario

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)
191 days
Longest growing season
2015
74 days
Shortest growing season
1976
159 days
Normal growing season
1991–2020 average

Top 10 Record Highs — September 11

# Temp Date
🏆 99°F September 11, 1973
2 99°F September 11, 1959
3 97°F September 11, 1990
4 95°F September 11, 1996
5 94°F September 11, 2015
6 94°F September 11, 2013
7 93°F September 11, 2011
8 93°F September 11, 1963
9 93°F September 11, 1960
10 93°F September 11, 1958

Top 5 Record Lows — September 11

# Temp Date
🥶 34°F September 11, 2005
2 36°F September 11, 1957
3 37°F September 11, 1988
4 38°F September 11, 1964
5 39°F September 11, 2010
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 — Ontario

threshold: 102°F (90th percentile of historical Jun–Aug highs)
5.2
Avg heat wave length
days (historical)
107°
Avg peak temp
during heat waves
7
Dangerous nights 2026
Overnights ≥ 70°F
0
Heat waves 2026
so far

Days ≥ 90°F Per Year

1945–2026
63
2026 so far
64
Avg/year 1970–2025
69
Avg/year (last 10 complete)
94
Most in a year (1967)

Average Daily High by Decade

Full year · complete decades only

Longest Heat Waves — Ontario

# Dates Days Peak Avg High Avg Overnight Low
🏆 Jul 22, 1971 – Aug 14, 1971 24 110°F (Aug 8) 106°F 62°F
2 Jun 15, 1961 – Jun 26, 1961 12 108°F (Jun 17) 105°F 60°F
3 Aug 10, 1967 – Aug 20, 1967 11 109°F (Aug 19) 106°F 55°F
4 Jul 13, 1960 – Jul 22, 1960 10 112°F (Jul 19) 107°F 62°F
5 Jul 17, 1956 – Jul 26, 1956 10 107°F (Jul 23) 104°F 59°F
6 Jun 28, 2021 – Jul 7, 2021 10 107°F (Jun 30) 105°F 68°F
7 Jul 15, 1959 – Jul 23, 1959 9 111°F (Jul 21) 107°F 59°F
8 Jul 3, 1968 – Jul 11, 1968 9 108°F (Jul 4) 105°F 61°F
9 Jul 16, 2024 – Jul 24, 2024 9 108°F (Jul 22) 105°F 68°F
10 Jul 25, 1973 – Aug 2, 1973 9 107°F (Aug 2) 105°F 60°F

Heat Waves Per Year

Warm Summer Nights (Jun–Aug)

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

51
2026 total
above-normal nights
29.1
Avg / summer
1970–2020
72
Most in a summer
2021

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 +0.13" per decade, about +1.0" 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 Ontario is tracking against normal, year to date

Daily High Temperature vs Normal

Above normal Below normal

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

Precipitation, Year to Date

6.55"
2026 YTD
Normal: 6.34"
+0.21"
0.39"
September so far
September normal: 0.29"
+0.10"
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 · Ontario is 0.21" 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)
53.8°F
Average temperature
10th-warmest of 78
+1.8°
vs. average
Normal: 52.1°F (1991–2020)
3.13"
Precipitation
16th-wettest of 68
+0.46"
vs. average
Normal: 2.67" · 117% of normal

Average Temperature by Year — Mar 1 – May 31

1946–2026 · 2026 highlighted · trend +0.24° per decade (warming since 1946)

Precipitation by Year — Mar 1 – May 31

1946–2026 · 2026 highlighted · trend +0.04" per decade (wetter since 1946)

Warmest Mar 1 – May 31 on Record

# Year Avg Temp
1 1992 56.1°F
2 2016 55.2°F
3 1987 55.0°F
4 2018 54.6°F
5 1994 54.4°F
6 2015 54.2°F
7 2025 54.0°F
8 2007 54.0°F
9 1949 53.9°F
10 2026 53.8°F

Coolest Mar 1 – May 31 on Record

# Year Avg Temp
1 2011 48.1°F
2 1975 48.2°F
3 1950 48.4°F
4 1948 48.5°F
5 1953 48.5°F
6 2010 48.7°F
7 1982 49.2°F
8 1964 49.3°F
9 2008 49.3°F
10 1970 49.6°F

Wettest Mar 1 – May 31 on Record

# Year Total
1 1957 5.95"
2 1983 5.25"
3 2006 5.13"
4 2019 5.13"
5 2011 4.99"
6 1953 4.81"
7 2023 4.37"
8 1958 4.20"
9 1996 4.04"
10 2012 3.70"

Driest Mar 1 – May 31 on Record

# Year Total
1 1966 0.88"
2 2021 0.95"
3 1972 0.95"
4 2013 1.01"
5 2007 1.05"
6 1974 1.08"
7 1999 1.12"
8 2008 1.16"
9 2016 1.19"
10 1968 1.19"
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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