Weather statistics, phenology and records
Monthly averages, climate normals, phenology, growing degree days and weather records for Mustamäe, Tallinn, Estonia.
Highest temperature
82.2 F
18 Jul
Lowest temperature
1.4 F
25 Jan
Total precipitation
9.0 in
65 Rain days
Strongest wind gust
46.1 mph
25 Apr
Monthly averages
| Month | Avg temp | Max temp | Min temp | Precipitation | Rain days |
|---|---|---|---|---|---|
| Jan | 18.5 F | 29.3 F | 1.4 F | 0.0 in | 0 |
| Feb | 19.6 F | 38.5 F | 2.8 F | 0.1 in | 3 |
| Mar | 39.9 F | 60.3 F | 29.3 F | 0.2 in | 9 |
| Apr | 42.1 F | 59.7 F | 29.8 F | 0.5 in | 5 |
| May | 53.4 F | 75.6 F | 35.8 F | 1.3 in | 9 |
| Jun | 62.4 F | 79.3 F | 48.4 F | 2.9 in | 13 |
| Jul | 64.6 F | 82.2 F | 47.5 F | 3.2 in | 19 |
| Aug | 63.5 F | 77.2 F | 54.5 F | 0.7 in | 7 |
| Sep | -- | -- | -- | -- | -- |
| Oct | -- | -- | -- | -- | -- |
| Nov | -- | -- | -- | -- | -- |
| Dec | -- | -- | -- | -- | -- |
Season Tracker 2026
🌸 Spring days
101
Days with T_max ≥ 15°C
☀️ Summer days
15
Days with T_max ≥ 25°C
🔥 Tropical days
0
Days with T_max ≥ 30°C
❄️ Frost days
73
Days with T_min < 0°C
🧊 Ice days
55
Days with T_max < 0°C
🌧️ Precipitation days
65
Days with rain ≥ 0.1 mm
Seasonal milestones
| Milestone | 2026 | Difference |
|---|---|---|
| 🌸 First spring day | 14 Mar | 32 days earlier |
| ☀️ First summer day | 04 Jun | 12 days later |
| 🌡️ First tropical day | — | — |
| ❄️ Last spring frost | 11 Apr | 8 days earlier |
| 🍂 First autumn frost | — | — |
| 🧊 First ice day | 01 Jan | 36 days earlier |
Growing Degree Days (base 10 °C) — Total GDD: 684
Peak GDD period
Shows daily GDD bars and a 14-day rolling total so warm stretches stand out.
Best 14-day period
19 Jun
– 2 Jul
130.2 GDD
Average per day: 9.3 GDD
What are Growing Degree Days?
Growing Degree Days (GDD) measure accumulated heat above a base temperature — not calendar days.
GDD = max(0, (Tmax + Tmin) / 2 − 10)
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
Highest temperature
91.2 F
29 Jul 2018
#2
90.0 F
21 Jun 2021
#3
89.8 F
22 Jun 2021
#4
89.8 F
10 Jul 2021
#5
89.2 F
28 Jun 2022
Lowest temperature
-2.6 F
04 Jan 2024
#2
-2.4 F
03 Jan 2024
#3
0.3 F
18 Feb 2021
#4
0.3 F
07 Dec 2021
#5
0.7 F
02 Jan 2024
Warmest day (avg)
81.5 F
21 Jun 2021
#2
81.5 F
22 Jun 2021
#3
80.8 F
29 Jul 2018
#4
80.6 F
10 Jul 2021
#5
80.4 F
27 Jun 2022
Coldest day (avg)
0.0 F
03 Jan 2024
#2
2.5 F
02 Jan 2024
#3
3.0 F
04 Jan 2024
#4
5.4 F
06 Dec 2021
#5
5.9 F
27 Feb 2018
Largest daily range
62.6 F
25 Aug 2024
#2
61.3 F
14 May 2018
#3
60.8 F
14 Apr 2018
#4
59.4 F
10 May 2021
#5
59.0 F
21 May 2019
Most precipitation (day)
1.1 in
30 Jun 2020
#2
1.0 in
11 Jun 2026
#3
0.9 in
20 Apr 2025
#4
0.9 in
02 Jul 2023
#5
0.9 in
14 Sep 2024
Highest rain rate
9.6 in
16 Dec 2023
#2
6.7 in
02 Aug 2017
#3
3.9 in
23 Jun 2021
#4
3.6 in
02 Aug 2018
#5
3.4 in
11 Jun 2024
Strongest wind gust
70.0 mph
07 Oct 2023
#2
59.1 mph
18 Dec 2019
#3
57.0 mph
19 Jun 2018
#4
57.0 mph
09 Mar 2019
#5
53.0 mph
27 Mar 2017
Highest average wind
22.6 mph
07 Oct 2023
#2
20.7 mph
17 Sep 2020
#3
20.2 mph
08 Oct 2023
#4
19.9 mph
02 Nov 2024
#5
19.4 mph
14 Jan 2022
Highest pressure
31 inHg
07 Feb 2025
#2
31 inHg
08 Feb 2025
#3
31 inHg
08 Feb 2017
#4
31 inHg
07 Feb 2017
#5
31 inHg
19 Mar 2022
Lowest pressure
28 inHg
17 Feb 2022
#2
28 inHg
10 Feb 2020
#3
28 inHg
30 Jan 2022
#4
28 inHg
05 Apr 2022
#5
29 inHg
11 Feb 2020
Highest humidity
99%
05 Apr 2018
#2
99%
04 Jul 2018
#3
99%
28 Dec 2018
#4
99%
11 May 2019
#5
99%
29 Dec 2023
Lowest humidity
1%
16 Nov 2025
#2
14%
22 May 2022
#3
19%
06 Apr 2019
#4
19%
29 Apr 2019
#5
19%
14 Mar 2022
Highest UV index
5.9
03 Jul 2025
#2
5.7
11 Jul 2021
#3
5.6
26 Jun 2021
#4
5.6
02 Jul 2025
#5
5.5
28 Jun 2020
Highest solar radiation
1088 W/m²
25 Jul 2017
#2
1068 W/m²
24 Jun 2025
#3
1044 W/m²
10 Jul 2022
#4
1042 W/m²
03 Jul 2019
#5
1036 W/m²
19 Jun 2017
Most sunshine hours
18.6 h
28 Jun 2023
#2
18.2 h
19 Jun 2023
#3
18.1 h
06 Jun 2022
#4
18.1 h
21 Jun 2022
#5
18.1 h
10 Jun 2023
Climate normals vs 2026
Departure from normal
| Month | Normal avg | Actual avg | Departure |
|---|---|---|---|
| Jan | 28.2 F | 18.5 F | -9.7 F |
| Feb | 28.2 F | 19.6 F | -8.6 F |
| Mar | 34.7 F | 39.9 F | +5.2 F |
| Apr | 41.9 F | 42.1 F | +0.2 F |
| May | 52.7 F | 53.4 F | +0.7 F |
| Jun | 62.4 F | 62.4 F | 0.0 F |
| Jul | 65.5 F | 64.6 F | -0.9 F |
| Aug | 64.0 F | 63.5 F | -0.5 F |
| Sep | -- | -- | -- |
| Oct | -- | -- | -- |
| Nov | -- | -- | -- |
| Dec | -- | -- | -- |
Compare periods
vs
vs
Highest temp
Lowest temp
Precipitation
Max wind
No data
Highest temp
Lowest temp
Precipitation
Max wind
No data