is August a good time to go to Germany and Austria?

We loved visiting Berlin and Munich in August. But we had air-conditioned lodgings, which often are difficult to find. Daylight lasts quite awhile, as you suggest. And the best answer to a heat spell is a nice cold beer, which is always readily available!

August is high season tourist wise. It depends where you are going. Spreewald or Kitzbühel? Some years can be hot and dry others cooler. Mosquitoes. Overall I think the humidity is moderate. You need to be more specific.

Depends on which parts of Germany or Austria, but generally speaking July and August are the hottest time of the year, and you can have periods over 90-95 F. This is frequently peak Summer. Humidity depends highly on were you go as well.
It will start to be more comfortable around the last week of August. That or early September might be more to your liking.

The daylight is of course longest around June 21. Nordic countries celebrate midsummer - such as Sweden. Ohers celebrate white nights.

By latitude Boston is located wide South of the whole German area, somewhere North of Rome (as comparison to Europe). Of course not fully comparable due to various factors which influence the climates of regions.

Summers can be warmer or cooler in Germany - depending on which place you choose and which weather system has established or no one.

So, yes August is also a good travel time with classic domestic vacation business at the shores and at some summer destinations. Take care of sun protection (cap, skin) and to have enough water with you - or refill your bottles at places on this map. The use of air condition is much more rarely in Germany compared to the US.

Be aware that some places in the same city can be much warmer than others (day and night). A micro-climate study from the city of Hamburg shows areas with + 5° C (K) over average, others - 3-4° C (K). So in total up to 8K difference at same region at same time.

If you want to travel South-Eastern parts of Germany (see map on this page) and do some outdoor activities be aware of ticks. They seem to be very active this year, also into Northern parts.

So far this year Germany has a very dry spring, esp. in Northern Germany there are regions in which only less than 5% of average rain were coming down in the last three months! Therefore we see wild fire danger levels going up very early this year.

Have a good journey.

The effects of the weather may be intolerable, the heat oppressive. Other than that trains can be exceedingly crowded. I've been in Germany numerous times in August, regardless of the weather.

One positive aspect of traveling in Austria and Germany in August is the hotel rates if reduced will be offered that month too. That's one incentive for going then.

August in Vienna is brutal. Everything is shriveled and ready to die. The most depressing month here after February, in my opinion. My parents came for August last year and they melted (and they had a/c).

Last two weeks of September and the first two weeks of October are, IMO, ideal.

You can find humidity info here:
Boston & Vienna
Scroll down the page to get humidity information.
The data used for the charts are from January 1, 1980 to December 31, 2016.
A comparison of the 2 cities here: Compare Boston vs Vienna
(see the 'Chance of Muggy Conditions' chart)

I live in South Georgia where it is hot in August. We did a Danube River cruise last July from Regensburg to Budapest. It got a little hot, but it was no were near hot in South Georgia.

Check out the link below and you will find it is usually not desperately hot in Vienna in August.
https://weatherspark.com/m/81358/8/Average-Weather-in-August-in-Vienna-Austria

I grew up in Louisiana and lived in West Africa for many years - I know hot and I know humidity.

Is Austria humid in August compared to Boston? Probably not. But that is not the issue. The issue is that very few places are air conditioned and homes/buildings are built for cold weather - meaning to retain the heat. I have been hotter here in August than I ever was in West Africa or Louisiana. I live here. Trust me when I say that August in Vienna is basically unbearable.

Of course if you are in the Alps, then it is an entirely different story.

Please believe Emily. I spent 17 days in Vienna last summer. With very, very few exceptions, the weather was unpleasantly hot. I did have air-conditioned lodgings, but it was often really icky outdoors. Here are the facts for July and August 2024:

Vienna weather July 2024

Vienna weather August 2024

Weather varies consideeably from year to year, so it's a good idea to check the stats for other years. You can do that via the pull-down box above the graph.

Looks like August 2024 was one of the Vienna's hottest Augusts.

Here's a comparison of August 2024 daily highs versus the highs from 1980 to 2016, 37 years.
https://weatherspark.com/h/m/81358/2024/8/Historical-Weather-in-August-2024-in-Vienna-Austria#Figures-Temperature

The average high is the dark red line. The top of the pink band is the temperature where 90% of all high temperatures for that day (1980-2016) were cooler. The August 2024 temperatures are the zig-zag grey lines.
For much of August 2024 the daily highs were hotter, sometimes much hotter, than 90% of all previous highs.

Maybe just as important, the daily lows were also hotter than the 90% band of daily lows (the top of the blue band) for many of the days of August 2024.
Looks like hotter travel is the future.

Further down the page there is a chart 'Humidity Comfort Levels in August 2024 in Vienna' which reports muggy comfort levels for not so many hours, which does seem to vary from the reported experiences here.

As for accuracy, I compared a couple of daily highs with other sources, and the sources were the same temperature.