Hanover Germany
Expected first-bloom dates for spring 2027, based on a degree-day temperature model and years of observations. 16 Oct 2026 status shown.
| Flower | Status today | Expected start | Likely range | Reliability | Model error (backtest) |
|---|---|---|---|---|---|
| Lilac | Season over | ~30 Apr 2027 | 17 Apr – 8 May | validated | 2.96 d |
| Forsythia | Season over | ~19 Mar 2027 | 7 Mar – 8 Apr | validated | 4.71 d |
| Wood anemone | Season over | ~25 Mar 2027 | 19 Mar – 3 Apr | validated | 4.56 d |
| Sweet cherry blossom | Season over | ~14 Apr 2027 | 5 Apr – 21 Apr | validated | 3.75 d |
| Horse chestnut | Season over | ~30 Apr 2027 | 20 Apr – 9 May | validated | 2.53 d |
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Lilac in Hanover validated
Season over. Next expected start ~30 Apr 2027. Likely start range (80% of past weather years): 17 Apr 2027 – 8 May 2027. Expected flowering length: ~20 days (measured in Sweden).
Backtested against 35 years of local observations at this city (leave-one-year-out); the model beat simple climatology.
- Typical error if the weather were known (model backtest, MAE): 2.96 days; 89% of years within ±5 days.
- Typical error of a long-range estimate like this one (spread of past years at this city, MAE): ±6.17 days. Months ahead, the weather is unknown, so expect about this much.
- Observations used: 35 years at this city (1991–2025).
Observed first-bloom date by year (city median of observers) vs. model expectation:
Forsythia in Hanover validated
Season over. Next expected start ~19 Mar 2027. Likely start range (80% of past weather years): 7 Mar 2027 – 8 Apr 2027. Expected flowering length: ~14 days (assumed, not measured).
Backtested against 35 years of local observations at this city (leave-one-year-out); the model beat simple climatology.
- Typical error if the weather were known (model backtest, MAE): 4.71 days; 69% of years within ±5 days.
- Typical error of a long-range estimate like this one (spread of past years at this city, MAE): ±11.23 days. Months ahead, the weather is unknown, so expect about this much.
- Observations used: 35 years at this city (1991–2025).
Observed first-bloom date by year (city median of observers) vs. model expectation:
Wood anemone in Hanover validated
Season over. Next expected start ~25 Mar 2027. Likely start range (80% of past weather years): 19 Mar 2027 – 3 Apr 2027. Expected flowering length: ~36 days (measured in Sweden).
Backtested against 35 years of local observations at this city (leave-one-year-out); the model beat simple climatology.
- Typical error if the weather were known (model backtest, MAE): 4.56 days; 69% of years within ±5 days.
- Typical error of a long-range estimate like this one (spread of past years at this city, MAE): ±5.8 days. Months ahead, the weather is unknown, so expect about this much.
- Observations used: 35 years at this city (1991–2025).
Observed first-bloom date by year (city median of observers) vs. model expectation:
Sweet cherry blossom in Hanover validated
Season over. Next expected start ~14 Apr 2027. Likely start range (80% of past weather years): 5 Apr 2027 – 21 Apr 2027. Expected flowering length: ~13 days.
Backtested against 24 years of local observations at this city (leave-one-year-out); the model beat simple climatology.
- Typical error if the weather were known (model backtest, MAE): 3.75 days; 79% of years within ±5 days.
- Typical error of a long-range estimate like this one (spread of past years at this city, MAE): ±5.03 days. Months ahead, the weather is unknown, so expect about this much.
- Observations used: 24 years at this city (1991–2023).
Observed first-bloom date by year (city median of observers) vs. model expectation:
Horse chestnut in Hanover validated
Season over. Next expected start ~30 Apr 2027. Likely start range (80% of past weather years): 20 Apr 2027 – 9 May 2027. Expected flowering length: ~14 days (assumed, not measured).
Backtested against 35 years of local observations at this city (leave-one-year-out); the model beat simple climatology.
- Typical error if the weather were known (model backtest, MAE): 2.53 days; 89% of years within ±5 days.
- Typical error of a long-range estimate like this one (spread of past years at this city, MAE): ±6.49 days. Months ahead, the weather is unknown, so expect about this much.
- Observations used: 35 years at this city (1991–2025).
Observed first-bloom date by year (city median of observers) vs. model expectation:
“Start” = first flowers open (BBCH 60), not the peak. Peak is usually later; we have no open peak data. Individual gardens differ by ±4–8 days from the city median. See How it works and Sources.