Wood anemone Anemone nemorosa
Expected first-bloom dates for spring 2027 in 16 cities.
| City | Status | Expected start | Likely range | Label | Model MAE (d) | Climatology MAE (d) | Obs. years |
|---|---|---|---|---|---|---|---|
| Berlin | Season over | ~26 Mar 2027 | 19 Mar – 6 Apr | validated | 4.37 | 5.44 | 35 |
| Hamburg | Season over | ~27 Mar 2027 | 20 Mar – 8 Apr | validated | 3.94 | 6.81 | 35 |
| Munich | Season over | ~29 Mar 2027 | 21 Mar – 4 Apr | validated | 3.97 | 6.42 | 35 |
| Cologne | Season over | ~23 Mar 2027 | 18 Mar – 30 Mar | validated | 4.44 | 6.32 | 35 |
| Frankfurt | Season over | ~23 Mar 2027 | 18 Mar – 29 Mar | validated | 3.26 | 5.55 | 35 |
| Stuttgart | Season over | ~23 Mar 2027 | 18 Mar – 30 Mar | approximate | 5.21 | 6.38 | 35 |
| Dresden | Season over | ~26 Mar 2027 | 20 Mar – 4 Apr | validated | 4.04 | 5.89 | 35 |
| Hanover | Season over | ~25 Mar 2027 | 19 Mar – 3 Apr | validated | 4.56 | 5.8 | 35 |
| Leipzig | Season over | ~25 Mar 2027 | 19 Mar – 4 Apr | validated | 4.83 | 6.49 | 35 |
| Nuremberg | Season over | ~27 Mar 2027 | 20 Mar – 3 Apr | validated | 4.7 | 7.28 | 35 |
| Stockholm | Season over | ~12 Apr 2027 | 1 Apr – 26 Apr | approximate | 6.68 | 5.78 | 17 |
| Uppsala | Season over | ~14 Apr 2027 | 5 Apr – 26 Apr | approximate | 6.44 | 4.76 | 17 |
| Gothenburg | Season over | ~4 Apr 2027 | 27 Mar – 17 Apr | approximate | 6.44 | 7.57 | 17 |
| Malmö | Season over | ~1 Apr 2027 | 25 Mar – 14 Apr | validated | 3.91 | 6.16 | 16 |
| Linköping | Season over | ~8 Apr 2027 | 31 Mar – 21 Apr | validated | 5 | 6.31 | 14 |
| Örebro | Season over | ~12 Apr 2027 | 2 Apr – 24 Apr | approximate | 5.27 | 6 | 15 |
Backtest (leave-one-year-out)
| Country | City-years | Model MAE | Simple climatology MAE | Within ±5 days |
|---|---|---|---|---|
| Germany | 350 | 4.33 d | 6.24 d | 70% |
| Sweden | 96 | 5.67 d | 6.09 d | 59% |
Model parameters
- Germany: sum of daily mean temperature above 0 °C from 1 Mar; bloom when the sum reaches 128 °C·days (fitted on 350 city-years)
- Sweden: sum of daily mean temperature above 0 °C from 1 Mar; bloom when the sum reaches 123 °C·days (fitted on 96 city-years)
MAE = mean absolute error in days. “Climatology” = just using the average date of the other years. Details and limits: How it works.