Better Weather for the Alps in Late May/Early June or September?

Karen, a great source for hourly past weather is timeanddate.com. My husband, a physicist, says that thunder is caused by lightening. There is no such thing as thunder without lightening.

Hello:

Thank you for your quick reply. For some reason, weather25, which has historical daily weather data, forecasts "patchy light rain with thunder," which is weird because, of course, your concern when you're hiking is lightning!

Thanks again. If someone reading this is looking for extended weather data, I would suggest Meteum, as well as the forementioned weather25.

Karen

I don’t think anyone can really predict the weather anymore. We were in many areas of Switzerland the last two weeks of August last year. It was green, hot and muggy. We had afternoon thunder and lightning storms in Appenzell and also in the Lauterbrunnen Valley where flash flooding was happening right after we left. We also had 3 days in Zermatt with clear views of the Matterhorn which is unusual. Maybe someone on here can fill in on how long this weather continued on into September. I also might add that it was extremely crowded everywhere we went.

We were in Wengen for one week in early September of 2023. The weather was absolutely perfect. We’re returning to Switzerland this September as well. For what it’s worth, the world renowned Jungfrau Marathon occurs in early September. I’d assume the organizers choose that time for a reason. (The marathoners ran right in front of our Airbnb. That was super exciting!)

I have been to Switzerland in both early June (June 3-8) and mid-September. In early June, there was still snow in some of the hiking areas and some cloudy and rainy days. It was very green with lots of wildflowers. In September, the weather seemed clearer but of course there was rain the day my husband ran the Jungfrau Marathon and clear blue skies the days afterwards! We are going this year in late June because of our schedules.

September, hands down.

We've (CA residents) been to Switzerland 28 times in past 30 years, basing in multiple different regions for the first 10 or so visits to explore where we really wanted to "land" for our annual trips there.

After all that enjoyable exploration we now always base in Wengen. Quintessential 'car-free' mountain village, with 2 wonderful grocery markets, a bakery, plenty of really good restaurants, lots to do from this base. Typically we stay 10 or more days. One year we based there for 3 months and never ran out of things to do and see. (Happened to be 2001, that was interesting)

With the caveat that no one can predict the weather months in advance (heck, in the Bernese Oberland best you can count on is 24 maybe 48 hours in advance) here are my thoughts:

May is too early, most of the nice scenic walks at elevation don't open until mid-June. May is mud season.

After mid-June you could be okay

However, in our three decades of annual visits we have totally settled on first half of September. Only once did the winter weather come in during early September. (Happened to be 9/11/2001 year, that was interesting) First half September the weather is typically the best of the year. A lot of the summer crowds have dispersed. I don't know where you are seeing brown in the alps in September but, in Wengen, all is still luxuriously green

How long will you be in country?