Expected to start in ~7 days (~2 May 2027). Likely start range (80% of past weather years): 22 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): 2.54 days; 91% of years within ±5 days.
Typical error of a long-range estimate like this one (spread of past years at this city, MAE): ±6.55 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 Nuremberg validated
Season over. Next expected start ~26 Mar 2028. Likely start range (80% of past weather years): 12 Mar 2028 – 8 Apr 2028. 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): 3.99 days; 77% of years within ±5 days.
Typical error of a long-range estimate like this one (spread of past years at this city, MAE): ±8.47 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 Nuremberg validated
Expected in bloom now (started ~27 Mar, ends ~2 May). Likely start range (80% of past weather years): 20 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): 4.7 days; 74% of years within ±5 days.
Typical error of a long-range estimate like this one (spread of past years at this city, MAE): ±7.28 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 Nuremberg validated
Expected in bloom now (started ~14 Apr, ends ~27 Apr). Likely start range (80% of past weather years): 6 Apr 2027 – 24 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): 3.1 days; 88% of years within ±5 days.
Typical error of a long-range estimate like this one (spread of past years at this city, MAE): ±4.65 days. Months ahead, the weather is unknown, so expect about this much.
Observations used: 24 years at this city (1991–2016).
Observed first-bloom date by year (city median of observers) vs. model expectation:
Horse chestnut in Nuremberg validated
Expected to start in ~6 days (~1 May 2027). Likely start range (80% of past weather years): 22 Apr 2027 – 8 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): 2.54 days; 91% of years within ±5 days.
Typical error of a long-range estimate like this one (spread of past years at this city, MAE): ±6.42 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.