| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
| ThuSunSunWedFriMonWedSatTueThuSunTue 1 | 1.4 | -8.5 | 7.0 | 12.7 | | | | | | | | |
| FriMonMonThuSatTueThuSunWedFriMonWed 2 | 1.5 | -10.2 | 11.9 | 13.4 | | | | | | | | |
| SatTueTueFriSunWedFriMonThuSatTueThu 3 | 0.5 | -6.6 | 13.7 | 6.5 | | | | | | | | |
| SunWedWedSatMonThuSatTueFriSunWedFri 4 | -2.3 | -6.5 | 6.6 | 9.5 | | | | | | | | |
| MonThuThuSunTueFriSunWedSatMonThuSat 5 | -1.3 | -3.4 | 8.8 | 17.5 | | | | | | | | |
| TueFriFriMonWedSatMonThuSunTueFriSun 6 | -2.9 | -0.5 | 12.8 | 7.9 | | | | | | | | |
| WedSatSatTueThuSunTueFriMonWedSatMon 7 | -4.2 | -0.4 | 15.0 | 7.6 | | | | | | | | |
| ThuSunSunWedFriMonWedSatTueThuSunTue 8 | -5.0 | -0.9 | 14.7 | 4.6 | | | | | | | | |
| FriMonMonThuSatTueThuSunWedFriMonWed 9 | -3.0 | -3.6 | 15.1 | 6.1 | | | | | | | | |
| SatTueTueFriSunWedFriMonThuSatTueThu 10 | -0.3 | -2.0 | 14.1 | 11.5 | | | | | | | | |
| SunWedWedSatMonThuSatTueFriSunWedFri 11 | -0.2 | 1.5 | 16.2 | 13.1 | | | | | | | | |
| MonThuThuSunTueFriSunWedSatMonThuSat 12 | -0.6 | 2.0 | 12.1 | 15.5 | | | | | | | | |
| TueFriFriMonWedSatMonThuSunTueFriSun 13 | -1.5 | 1.1 | 14.2 | 13.9 | | | | | | | | |
| WedSatSatTueThuSunTueFriMonWedSatMon 14 | 2.1 | -1.6 | 16.7 | 13.7 | | | | | | | | |
| ThuSunSunWedFriMonWedSatTueThuSunTue 15 | 2.6 | -3.1 | 9.1 | 12.2 | | | | | | | | |
| FriMonMonThuSatTueThuSunWedFriMonWed 16 | 1.2 | -6.4 | 6.6 | 14.4 | | | | | | | | |
| SatTueTueFriSunWedFriMonThuSatTueThu 17 | -1.0 | -6.7 | 5.7 | 13.6 | | | | | | | | |
| SunWedWedSatMonThuSatTueFriSunWedFri 18 | -5.5 | -1.6 | 12.1 | 17.9 | | | | | | | | |
| MonThuThuSunTueFriSunWedSatMonThuSat 19 | -3.9 | -1.7 | 10.6 | 14.6 | | | | | | | | |
| TueFriFriMonWedSatMonThuSunTueFriSun 20 | -2.1 | 0.8 | 9.4 | | | | | | | | | |
| WedSatSatTueThuSunTueFriMonWedSatMon 21 | -4.3 | 3.8 | 10.3 | | | | | | | | | |
| ThuSunSunWedFriMonWedSatTueThuSunTue 22 | -3.0 | 4.5 | 13.0 | | | | | | | | | |
| FriMonMonThuSatTueThuSunWedFriMonWed 23 | -6.7 | 5.3 | 15.3 | | | | | | | | | |
| SatTueTueFriSunWedFriMonThuSatTueThu 24 | -4.0 | 3.6 | 14.7 | | | | | | | | | |
| SunWedWedSatMonThuSatTueFriSunWedFri 25 | -3.9 | 2.8 | 14.7 | | | | | | | | | |
| MonThuThuSunTueFriSunWedSatMonThuSat 26 | -1.8 | 8.5 | 6.8 | | | | | | | | | |
| TueFriFriMonWedSatMonThuSunTueFriSun 27 | -0.1 | 12.3 | 10.5 | | | | | | | | | |
| WedSatSatTueThuSunTueFriMonWedSatMon 28 | -0.7 | 14.8 | 12.6 | | | | | | | | | |
| ThuSunWedFriMonWedSatTueThuSunTue 29 | -4.4 | | 9.5 | | | | | | | | | |
| FriMonThuSatTueThuSunWedFriMonWed 30 | -5.1 | | 9.8 | | | | | | | | | |
| SatTueSunFriMonSatThu 31 | -7.9 | | 9.0 | | | | | | | | | |
| Avg: |
-2.1 | -0.1 | 11.6 | * 11.9 | | | | | | | | |
| Hi: |
2.6 | 14.8 | 16.7 | * 17.9 | | | | | | | | |
| Lo: |
-7.9 | -10.2 | 5.7 | * 4.6 | | | | | | | | |
| Note: |
*Incomplete dataset. |
| Avg | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
| 2026 | -2.1 | -0.1 | 11.6 | * 11.9 | | | | | | | | |
| 2025 | 3.4 | 2.7 | 10.5 | 15.7 | 16.1 | 22.0 | 24.2 | 22.4 | 20.0 | 11.7 | 5.9 | 4.7 |
| 2024 | 2.3 | 6.7 | 10.2 | 14.4 | 23.1 | 23.8 | 25.1 | 24.9 | 21.6 | 13.3 | 5.9 | 4.8 |
| 2023 | 4.4 | 4.1 | 7.3 | 12.7 | 19.4 | 24.2 | 23.9 | 23.7 | 23.3 | 13.0 | 5.8 | 3.8 |
| 2022 | 3.6 | 5.4 | 8.5 | 11.3 | 17.8 | 24.3 | 23.3 | 26.5 | 16.3 | 14.3 | 6.4 | 2.0 |
| 2021 | 1.1 | 2.3 | 7.0 | 10.5 | 17.8 | 26.5 | 26.1 | 20.9 | 18.3 | 12.9 | 7.1 | 1.3 |
| 2020 | 5.0 | 6.1 | 8.2 | 13.7 | 15.5 | 23.3 | 22.6 | 25.8 | 20.1 | 13.2 | 8.1 | 3.1 |
| 2019 | 1.4 | 5.5 | 8.7 | 14.8 | 16.5 | 28.2 | 22.2 | 25.4 | 17.9 | 13.2 | 7.1 | 4.7 |
| 2018 | 2.4 | -0.3 | 3.3 | 17.2 | 23.4 | 24.4 | 24.9 | 25.4 | 20.1 | 14.5 | 6.7 | 3.4 |
| 2017 | 0.4 | 2.4 | 8.9 | 10.5 | 18.9 | 21.6 | 22.0 | 23.0 | 17.1 | 12.4 | 6.4 | 3.6 |
| 2016 | -0.7 | 4.5 | 6.6 | 13.4 | 21.6 | 24.6 | 23.0 | 21.5 | 19.9 | 9.1 | 4.3 | 3.1 |
| 2015 | 3.1 | 3.7 | 8.6 | 12.3 | 18.0 | 21.1 | 23.8 | 27.2 | 18.4 | 11.3 | 7.7 | 6.4 |
| 2014 | -1.0 | 5.8 | 10.4 | 15.8 | 18.3 | 20.9 | 27.0 | 23.1 | 19.8 | 13.7 | 6.7 | 2.5 |
| 2013 | -0.6 | 1.7 | 1.7 | 12.0 | 21.7 | 23.3 | 24.0 | 24.0 | 16.9 | 13.5 | 6.9 | 4.6 |
| 2012 | | | | | | | | | | | * 4.3 | -0.3 |
| Avg | 1.6 | 3.6 | 8.0 | * 13.3 | 19.1 | 23.7 | 24.0 | 24.1 | 19.2 | 12.8 | * 6.4 | 3.4 |
| | Spring | Summer | Autumn | Winter |
| | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Jan | Feb |
| 2026Hi | 16.7 | *17.9 | | | | | | | | | | |
| Lo | 5.7 | *4.6 | | | | | | | | | | |
| Avg | 11.6 | *11.9 | | | | | | | | | | |
| Avg | * 11.7 | | | |
| 2025Hi | 18.0 | 27.2 | 23.7 | 31.4 | 37.2 | 32.8 | 28.3 | 15.8 | 12.4 | 11.0 | 2.6 | 14.8 |
| Lo | 2.2 | 4.3 | 8.5 | 15.4 | 16.4 | 12.8 | 11.7 | 7.6 | -3.3 | -1.9 | -7.9 | -10.2 |
| Avg | 10.5 | 15.7 | 16.1 | 22.0 | 24.2 | 22.4 | 20.0 | 11.7 | 5.9 | 4.7 | -2.1 | -0.1 |
| Avg | 14.1 | 22.9 | 12.5 | 0.9 |
| 2024Hi | 21.7 | 27.5 | 29.1 | 33.7 | 32.3 | 31.9 | 30.3 | 19.3 | 14.1 | 10.4 | 9.1 | 7.4 |
| Lo | 2.7 | 3.4 | 14.6 | 16.0 | 16.8 | 17.4 | 12.6 | 9.8 | 0.8 | 1.5 | -1.3 | -2.1 |
| Avg | 10.2 | 14.4 | 23.1 | 23.8 | 25.1 | 24.9 | 21.6 | 13.3 | 5.9 | 4.8 | 3.4 | 2.7 |
| Avg | 15.9 | 24.6 | 13.6 | 3.7 |
| 2023Hi | 17.1 | 22.6 | 26.8 | 29.6 | 33.5 | 33.2 | 28.6 | 23.4 | 13.5 | 8.8 | 8.1 | 13.4 |
| Lo | 1.4 | 3.7 | 10.2 | 14.9 | 18.6 | 16.6 | 16.3 | 4.5 | -2.4 | -2.6 | -5.3 | 0.3 |
| Avg | 7.3 | 12.7 | 19.4 | 24.2 | 23.9 | 23.7 | 23.3 | 13.0 | 5.8 | 3.8 | 2.3 | 6.7 |
| Avg | 13.1 | 24.0 | 14.0 | 4.2 |
| 2022Hi | 16.1 | 17.1 | 28.2 | 34.1 | 37.2 | 34.8 | 20.8 | 19.0 | 13.2 | 12.2 | 14.9 | 9.1 |
| Lo | 1.6 | 3.6 | 10.8 | 16.0 | 15.0 | 18.5 | 13.3 | 8.1 | -0.9 | -6.0 | -0.6 | -0.5 |
| Avg | 8.5 | 11.3 | 17.8 | 24.3 | 23.3 | 26.5 | 16.3 | 14.3 | 6.4 | 2.0 | 4.4 | 4.1 |
| Avg | 12.5 | 24.7 | 12.4 | 3.5 |
| | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Jan | Feb |
| 2021Hi | 19.3 | 20.0 | 30.2 | 36.3 | 33.5 | 28.6 | 27.6 | 18.8 | 13.0 | 10.6 | 10.2 | 8.6 |
| Lo | 0.2 | 5.0 | 8.4 | 18.7 | 20.2 | 15.3 | 12.1 | 8.2 | 1.1 | -5.1 | -0.2 | 1.0 |
| Avg | 7.0 | 10.5 | 17.8 | 26.5 | 26.1 | 20.9 | 18.3 | 12.9 | 7.1 | 1.3 | 3.6 | 5.4 |
| Avg | 11.8 | 24.5 | 12.8 | 3.4 |
| 2020Hi | 16.0 | 21.2 | 25.2 | 30.4 | 29.5 | 32.1 | 28.0 | 19.3 | 15.1 | 7.7 | 7.4 | 14.8 |
| Lo | 2.1 | 5.3 | 10.3 | 16.0 | 17.2 | 18.0 | 15.9 | 8.5 | 3.2 | -2.1 | -5.7 | -7.6 |
| Avg | 8.2 | 13.7 | 15.5 | 23.3 | 22.6 | 25.8 | 20.1 | 13.2 | 8.1 | 3.1 | 1.1 | 2.3 |
| Avg | 12.4 | 23.9 | 13.8 | 2.2 |
| 2019Hi | 17.3 | 27.3 | 25.5 | 36.1 | 32.4 | 32.0 | 31.3 | 19.4 | 11.4 | 9.4 | 10.1 | 12.7 |
| Lo | 4.2 | 3.2 | 10.1 | 17.7 | 15.6 | 19.1 | 11.5 | 5.9 | 1.0 | 0.4 | 2.3 | 2.5 |
| Avg | 8.7 | 14.8 | 16.5 | 28.2 | 22.2 | 25.4 | 17.9 | 13.2 | 7.1 | 4.7 | 5.0 | 6.1 |
| Avg | 13.3 | 25.2 | 12.8 | 5.3 |
| 2018Hi | 13.9 | 26.8 | 32.0 | 32.1 | 33.5 | 34.1 | 28.2 | 21.3 | 15.3 | 9.1 | 6.3 | 13.0 |
| Lo | -8.2 | 5.3 | 14.2 | 17.3 | 16.7 | 18.7 | 11.9 | 5.5 | -1.9 | -2.0 | -6.1 | -0.7 |
| Avg | 3.3 | 17.2 | 23.4 | 24.4 | 24.9 | 25.4 | 20.1 | 14.5 | 6.7 | 3.4 | 1.4 | 5.5 |
| Avg | 14.6 | 24.9 | 13.8 | 3.4 |
| 2017Hi | 19.2 | 22.8 | 29.3 | 29.6 | 31.9 | 31.7 | 20.6 | 19.9 | 12.1 | 8.2 | 8.8 | 6.0 |
| Lo | 2.1 | 4.6 | 6.8 | 15.7 | 16.2 | 16.8 | 14.6 | 5.3 | 0.9 | -2.4 | -4.7 | -8.4 |
| Avg | 8.9 | 10.5 | 18.9 | 21.6 | 22.0 | 23.0 | 17.1 | 12.4 | 6.4 | 3.6 | 2.4 | -0.3 |
| Avg | 12.8 | 22.2 | 12.0 | 2.0 |
| | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Jan | Feb |
| 2016Hi | 15.4 | 23.6 | 29.7 | 37.4 | 30.1 | 29.1 | 27.3 | 16.3 | 10.3 | 8.9 | 3.4 | 11.2 |
| Lo | 2.1 | 6.6 | 9.5 | 15.6 | 15.4 | 15.5 | 14.6 | 6.4 | 0.3 | -0.9 | -6.0 | -7.0 |
| Avg | 6.6 | 13.4 | 21.6 | 24.6 | 23.0 | 21.5 | 19.9 | 9.1 | 4.3 | 3.1 | 0.4 | 2.4 |
| Avg | 13.9 | 23.0 | 11.1 | 1.9 |
| 2015Hi | 16.8 | 22.7 | 24.1 | 31.7 | 36.5 | 33.2 | 29.8 | 20.0 | 14.0 | 11.8 | 8.2 | 8.3 |
| Lo | 3.1 | 5.0 | 11.5 | 14.4 | 13.8 | 20.9 | 12.5 | 5.0 | 0.8 | -3.0 | -10.0 | 0.8 |
| Avg | 8.6 | 12.3 | 18.0 | 21.1 | 23.8 | 27.2 | 18.4 | 11.3 | 7.7 | 6.4 | -0.7 | 4.5 |
| Avg | 13.0 | 24.1 | 12.4 | 3.4 |
| 2014Hi | 19.3 | 22.6 | 32.1 | 30.8 | 34.7 | 34.0 | 26.0 | 19.4 | 14.2 | 10.7 | 9.9 | 8.3 |
| Lo | 3.0 | 7.2 | 9.4 | 14.2 | 16.2 | 15.9 | 11.5 | 3.1 | -2.5 | -4.1 | -1.6 | -0.5 |
| Avg | 10.4 | 15.8 | 18.3 | 20.9 | 27.0 | 23.1 | 19.8 | 13.7 | 6.7 | 2.5 | 3.1 | 3.7 |
| Avg | 14.8 | 23.7 | 13.4 | 3.1 |
| 2013Hi | 10.4 | 25.0 | 31.1 | 35.9 | 35.9 | 33.8 | 24.2 | 18.1 | 10.6 | 7.1 | 9.5 | 9.2 |
| Lo | -3.6 | 1.4 | 14.5 | 13.9 | 17.7 | 16.1 | 11.1 | 7.9 | 1.9 | -0.4 | -11.8 | 1.9 |
| Avg | 1.7 | 12.0 | 21.7 | 23.3 | 24.0 | 24.0 | 16.9 | 13.5 | 6.9 | 4.6 | -1.0 | 5.8 |
| Avg | 11.8 | 23.8 | 12.4 | 3.1 |
| 2012Hi | | | | | | | | | *5.0 | 7.1 | 8.1 | 5.2 |
| Lo | | | | | | | | | *3.1 | -9.6 | -8.3 | -2.6 |
| Avg | | | | | | | | | *4.3 | -0.3 | -0.6 | 1.7 |
| Avg | | | * 4.3 | 0.3 |
| Note: |
*Incomplete dataset. |