Radweg D11: Ostsee – Oberbayern, stage 4: Potsdam → Gräfenhainichen
On stage 4 (Potsdam → Gräfenhainichen, 124 km) the best month is September: 81% of days were dry with highs of 10–30 °C, and riding Gräfenhainichen → Potsdam meant an average tailwind of 2.4 km/h (ERA5 2006–2025, 9:00–18:00).
← Radweg D11: Ostsee – Oberbayern (Whole route)
Weather by month
| Month | Good days | Rain days ≥ 1 mm | Rain, mm | Avg high | Days ≥ 30 °C | Days < 10 °C | Daylight, h |
|---|---|---|---|---|---|---|---|
| January | 5% | 24% | 56 | 3 °C | 0% | 92% | 8.2 † |
| February | 13% | 19% | 40 | 5 °C | 0% | 83% | 9.8 † |
| March | 36% | 23% | 43 | 9 °C | 0% | 57% | 11.7 |
| April | 69% | 18% | 33 | 15 °C | 0% | 20% | 13.8 |
| May | 77% | 21% | 56 | 19 °C | 1% | 2% | 15.7 |
| June | 72% | 22% | 55 | 23 °C | 8% | 0% | 16.7 |
| July | 63% | 24% | 81 | 25 °C | 14% | 0% | 16.3 |
| August | 68% | 21% | 61 | 24 °C | 11% | 0% | 14.6 |
| September | 81% | 16% | 47 | 20 °C | 2% | 0% | 12.6 |
| October | 71% | 19% | 51 | 14 °C | 0% | 13% | 10.5 † |
| November | 30% | 18% | 48 | 8 °C | 0% | 64% | 8.7 † |
| December | 7% | 21% | 52 | 5 °C | 0% | 89% | 7.8 † |
Best months are all months within 3 percentage points of the best one. † less than 11 hours of daylight — long stages get tight.
Wind by month
| Month | Wind Potsdam → Gräfenhainichen, km/h | Headwind > 15 km/h, Potsdam → Gräfenhainichen | Headwind > 15 km/h, Gräfenhainichen → Potsdam | Better way |
|---|---|---|---|---|
| January | −5.6 | 19% | 2% | Gräfenhainichen → Potsdam |
| February | −4.1 | 14% | 3% | Gräfenhainichen → Potsdam |
| March | −2.3 | 11% | 3% | Gräfenhainichen → Potsdam |
| April | −0.3 | 6% | 4% | either |
| May | −0.5 | 7% | 4% | either |
| June | −1.5 | 6% | 2% | either |
| July | −2.7 | 7% | 1% | Gräfenhainichen → Potsdam |
| August | −3.0 | 7% | 1% | Gräfenhainichen → Potsdam |
| September | −2.4 | 7% | 2% | Gräfenhainichen → Potsdam |
| October | −4.3 | 12% | 2% | Gräfenhainichen → Potsdam |
| November | −5.4 | 14% | 1% | Gräfenhainichen → Potsdam |
| December | −6.6 | 19% | 1% | Gräfenhainichen → Potsdam |
Along the route (sections of about 25 km)
| km | Heading | Tailwind in September, km/h |
|---|---|---|
| 400–426 | SW | −2.7 |
| 426–451 | SW | −3.6 |
| 451–476 | S | −1.1 |
| 476–501 | S | −1.1 |
| 501–524 | SW | −3.5 |
Other stages
- Warnemünde → Waren 142 km
- Waren → Zehdenick 138 km
- Zehdenick → Potsdam 122 km
- Potsdam → Gräfenhainichen 124 km
- Gräfenhainichen → Halle (Saale) 142 km
- Halle (Saale) → Jena 114 km
- Jena → Rosenthal 137 km
- Rosenthal → Lichtenfels 134 km
- Lichtenfels → Nuremberg 117 km
- Nuremberg → Kelheim 128 km
- Kelheim → Freising 127 km
- Freising → Rosenheim 105 km
- Rosenheim → Freilassing 90 km
How to read the numbers
Wind is the 10 m wind of a 25-km grid cell, daytime hours 9:00–18:00 local solar time; at saddle height in a sheltered valley it is weaker, on a coast or ridge stronger. A positive value is a tailwind. ERA5 slightly over-counts days with ≥ 1 mm of rain (by about 5–7 percentage points) and underestimates daily highs by 1–2 °C. Good day = less than 1 mm of rain between 9:00 and 18:00 (riding hours, local solar time) and a high between 10 and 30 °C; rain at night or in the evening does not spoil it.