Luxembourg Climate Guide: Weather by Season & Region

Travel time: Year-round

Luxembourg features a temperate oceanic climate, heavily influenced by its position at the crossroads of Atlantic maritime systems and continental air masses from Eastern Europe. The weather is characterized by moderate temperatures and persistent, year-round humidity. While the country is small, its diverse topography—from the rugged hills of the north to the river valleys of the east—creates distinct regional variations.

The Daily Rhythm

A typical day in Luxembourg is often defined by its soft, diffused light and frequent cloud cover, particularly in the mornings. The diurnal temperature range is generally narrow during the winter but can widen significantly in late spring and summer. It is common to experience rapid shifts in weather within a single day—a phenomenon locals call "March showers" (even when they occur in April), where bright sun is followed by a sudden, heavy downpour before returning to blue skies.

Seasonal Trends

Spring (March – May)

Spring is a period of transition and high unpredictability. March starts cool with average highs around 9°C (49°F), but by May, temperatures often settle near a comfortable 18°C (64°F). This is the season when the country "wakes up," marked by the return of migratory gray cranes. Early spring is frequently breezy, with unsettled weather that keeps the landscape lush and green.

Summer (June – August)

Summers are mild and pleasant rather than scorching. July is the warmest month, with average highs reaching 23°C (73°F). However, the region is increasingly prone to occasional heatwaves where temperatures can spike above 30°C (86°F). Late afternoon thunderstorms are common, especially in the more humid southern plains. These storms provide a sudden cooling effect after a warm day.

Autumn (September – November)

Autumn begins with the "Indian Summer" in September and early October, offering crisp, golden days that are ideal for viewing the foliage in the Ardennes forests. As November approaches, the weather turns gray and damp. This period sees the most frequent rainfall and a steady increase in wind speeds as Atlantic low-pressure systems move across the continent.

Winter (December – February)

Winters are cold and often overcast, with average temperatures hover around 0°C to 3°C (32°F to 37°F). While snow used to be a reliable fixture, it has become less predictable in recent years. Today, it frequently falls and melts within 24 hours in the capital, though it lingers longer on the higher plateaus. January is typically the windiest and darkest month, with the sun appearing for only about 1.5 to 2 hours per day on average.

Regional Microclimates

  • Oesling (The Ardennes): The northern third of the country is higher in elevation (up to 560m) and significantly cooler. It receives about 1,000mm of rain annually—roughly 30% more than the south—and is the most likely place to see deep snow packs and sub-zero temperatures.
  • Gutland (The Good Land): The southern and central regions, including Luxembourg City, are more sheltered. Temperatures here are typically 2°C to 3°C warmer than in the north.
  • Moselle Valley: Located in the east, this valley sits at the lowest elevation in the country. It acts as a sun trap, creating a microclimate that is drier and warmer, making it the premier region for the country's vineyards.

Local Perspective & Historical Context

Locals have mastered the art of "hygge-style" living to combat the long, gray winters, focusing on bright indoor lighting and vibrant Christmas markets. Historically, Luxembourg’s climate was more continental, with reliably frozen rivers and heavy snow. However, long-term data shows a warming trend of approximately 1.5°C over the last 80 years, leading to shorter winters and more frequent summer thermal stress in urbanized areas like the capital.

Unique Phenomena

  • The Atlantic Westerlies: These prevailing winds carry moist air from the ocean, ensuring that Luxembourg rarely experiences true drought but also contributing to its reputation for constant gray skies.
  • Black Ice (Verglas): A common winter hazard, particularly on the winding roads of the Ardennes, where clear nights following a damp day cause invisible layers of ice to form instantly.
  • The Feeling: Beyond the numbers, Luxembourg often feels "damp-cold" in winter, where the high humidity makes the air bite more than the thermometer suggests. Conversely, summer evenings feel brilliantly fresh and clean due to the surrounding vast forest cover.