Tailwind Atlas

RAVeL W9 La Véloroute grandeur Nature: which way and when to ride

The best month for RAVeL W9 La Véloroute grandeur Nature is September: 73% of days were dry with highs of 10–30 °C. In September, riding Martelange → Raeren meant an average tailwind of 2.6 km/h (ERA5 2006–2025, daytime 9:00–18:00).

ERA5 2006–2025 · OpenStreetMap · Methodology and sources

155 kmLength
SeptemberBest months
Martelange → RaerenBetter direction in the best month
2.6 km/hAverage tailwind in the best month
73%Dry days with 10–30 °C
June · 62%Best summer month
Start: Raeren · Finish: Martelange · Route geometry: OpenStreetMap / Waymarked Trails

Also passes through Germany

Weather by month

MonthGood daysRain days ≥ 1 mmRain, mmAvg highDays ≥ 30 °CDays < 10 °CDaylight, h
January2%33%953 °C0%96%8.5 †
February8%31%755 °C0%91%10.0 †
March29%33%818 °C0%65%11.7
April53%30%6213 °C0%33%13.7
May59%38%8916 °C0%7%15.4
June62%37%10120 °C1%0%16.4
July60%37%9621 °C4%0%16.0
August62%36%9821 °C3%0%14.5
September73%27%7717 °C0%2%12.5
October58%27%8113 °C0%23%10.6 †
November18%33%807 °C0%75%8.9 †
December3%32%984 °C0%93%8.1 †

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

MonthWind Raeren → Martelange, km/hHeadwind > 15 km/h, Raeren → MartelangeHeadwind > 15 km/h, Martelange → RaerenBetter way
January−6.024%3%Martelange → Raeren
February−5.323%5%Martelange → Raeren
March−2.417%7%Martelange → Raeren
April−0.111%8%either
May−0.411%7%either
June−0.610%5%either
July−2.312%3%Martelange → Raeren
August−3.311%2%Martelange → Raeren
September−2.612%4%Martelange → Raeren
October−5.521%3%Martelange → Raeren
November−6.925%3%Martelange → Raeren
December−7.226%3%Martelange → Raeren

Along the route (sections of about 25 km)

kmHeadingTailwind in September, km/h
0–26SE+0.9
26–51S−3.8
51–76S−2.3
76–101SW−4.4
101–127SW−3.7
127–155S−2.2

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.

OpenStreetMap · Waymarked Trails