Mother-Daughter trip to Austria

May is a bit risky, but would allow one to see snow. September weather is more predictable, but snow may have all melted by then.

How much time do you have?

If you can swing it mid June in the Alps is just about perfect in my opinion. There is always bad weather possible, but with the clear blue skies and mountain blumes it can be fantastic. May you can still find snow in higher elevations. September can be rainy. You probably will see more tourists in September. You might want to check on mountain lift opening/running times in May. Some Hütte don't open until mid June.

Hi Tanya,
What a wonderful trip for you and your Mom. We were in Germany/Austria in May 2023. We had clouds/rain in the alps. My husband and I had gone to the Swiss Alps in June and the weather was perfect. I felt bad that my kids did not have the same view of the Alps that we had on our honeymoon, but we had a GREAT trip.
Here is my trip report. It was a wonderful combination of nature/countryside with the lovely sights in Salzburg and Vienna. Please lmk if I can help with your planning.
Trip Report: Germany/Austria May 2023 Part I

Tanya,
Here is link to my trip report.. I think you can copy link below... I got great tips/advise on this forum for planning this trip. It's a beautiful place to visit.
https://community.ricksteves.com/travel-forum/trip-reports/trip-report-germany-austria-may-2023-part-i

Joanne

September will be perfect. Still warm, but possibly some snowy peaks. May might be a bit early for the Alps. If you go in September, please Google Almabtrieb, which is the process of bringing the cows down from the mountains. The cows are decorated with flowers and bells, the villages have great festivals.

Here a good link on Almabtrieb - https://www.austria.info/en-us/inspiration/cattle-processions/