Weather statistics, phenology and records
Monthly averages, climate normals, phenology, growing degree days and weather records for West Hartford, CT.
Highest temperature
87.4 F
02 Oct
Lowest temperature
33.4 F
07 Oct
Total precipitation
9.3 in
9 Rain days
Strongest wind gust
23.9 mph
26 Sep
Monthly averages
| Month | Avg temp | Max temp | Min temp | Precipitation | Rain days |
|---|---|---|---|---|---|
| Jan | -- | -- | -- | -- | -- |
| Feb | -- | -- | -- | -- | -- |
| Mar | -- | -- | -- | -- | -- |
| Apr | -- | -- | -- | -- | -- |
| May | -- | -- | -- | -- | -- |
| Jun | -- | -- | -- | -- | -- |
| Jul | -- | -- | -- | -- | -- |
| Aug | -- | -- | -- | -- | -- |
| Sep | 59.4 F | 71.1 F | 54.7 F | 5.1 in | 4 |
| Oct | 58.8 F | 87.4 F | 33.4 F | 4.2 in | 5 |
| Nov | -- | -- | -- | -- | -- |
| Dec | -- | -- | -- | -- | -- |
Season Tracker 2026
Seasonal milestones
| Milestone | 2026 | Difference |
|---|---|---|
| 🌸 First spring day | 26 Sep | — |
| ☀️ First summer day | 02 Oct | — |
| 🌡️ First tropical day | 02 Oct | — |
| ❄️ Last spring frost | — | — |
| 🍂 First autumn frost | — | — |
| 🧊 First ice day | — | — |
Growing Degree Days (base 10 °C) — Total GDD: 115
Peak GDD period
Shows daily GDD bars and a 14-day rolling total so warm stretches stand out.
Best 14-day period
26 Sep
– 9 Oct
81.0 GDD
Average per day: 5.8 GDD
What are Growing Degree Days?
Growing Degree Days (GDD) measure accumulated heat above a base temperature — not calendar days.
Each day contributes a value equal to how many degrees the average temperature exceeds 10 °C. A day with a high of 26 °C and a low of 12 °C contributes (26 + 12) / 2 − 10 = 9 GDD.
The total GDD for a year is the sum of all daily values. A warm summer can easily produce 1 000 – 1 500 GDD, which is why the total is much larger than 365.
Base temperature: 10 °C (growing threshold for most plants in temperate climates).
All-time records
Climate normals vs 2026
Departure from normal
| Month | Normal avg | Actual avg | Departure |
|---|---|---|---|
| Jan | -- | -- | -- |
| Feb | -- | -- | -- |
| Mar | -- | -- | -- |
| Apr | -- | -- | -- |
| May | -- | -- | -- |
| Jun | -- | -- | -- |
| Jul | -- | -- | -- |
| Aug | -- | -- | -- |
| Sep | 59.4 F | 59.4 F | 0.0 F |
| Oct | 58.1 F | 58.8 F | +0.7 F |
| Nov | -- | -- | -- |
| Dec | -- | -- | -- |
Compare periods
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