Where to go in August?

I am looking at Poland. Farther north, so cooler. And relatively inexpensive compared to most of Western Europe.

We spent almost 3 weeks in Poland a few years ago. Loved it. Poland and the Baltic states would be good places to research. You might also consider Scandinavia.

Hello

I do not know if this would work for you but Iceland might be very nice in August and I think that you can get a good deal on flights from Boston.

Have you gone to Alaska yet? August is a good month to go to Alaska.

Great Britain. I am talking about England as well as Scotland and Wales.

As someone else suggested, anywhere in Scandinvia.

These places might be on the expensive side But I think that August will be an expensive month to travel wherever you go.

The Baltics have the advantage of being both cooler and less crowded, but interesting.

"Not hot and not too expensive" is not a lot to go on. Maybe you could tell us what your interests are, who you're traveling with, whether you prefer to get a car or use public transportation.
Ireland generally has good weather in August. Of course, that could change in 20 minutes or so. Outside of Dublin, accommodations aren't unreasonable. With a car and some imagination, you can find very reasonable prices outside the big tourist towns.
How about Belgium and Netherlands? While Amsterdam is very expensive, I don't think that's the case everywhere. The Belgian coast is very nice.

Last July and August we visited Scotland, England, Belgium, Netherlands, northern Germany, Denmark, Sweden, Norway, Poland and Czechia. Weather was generally delightful, as I would expect those places to be at that time of year.

If you like the idea of Scandinavian climate but find the costs prohibitive, why not consider the Baltic countries of Estonia, Latvia and Lithuania? Combined with Poland they'd make a wonderful summer vacation IMO.

Freisland. The islands.

Here are a few places I would consider:
Belgium / Netherlands (be aware that Amsterdam can be crowded)
Northern Germany (Bremen, Hamburg, Baltic coast)
Baltic countries
Alps

Remember that for mild temperatures, coasts are better than inland, green spaces are better than pavement, and countryside is better than city. Consider renting a place in a coastal town--places like Hindeloopen, Aurich/Greetsiel, Glückstadt, St. Peter-Ording, Schleswig, Wismar, Heringsdorf. These are BEAUTIFUL towns in their own right, and they are near other great sites.

Alternatively, you could do mountains--Grindelwald/Interlaken, Liechtenstein, Garmisch-Partenkirchen / Innsbruck, Salzburg, Hallstadt

And of course in northern Italy: Lago di Como, Bolzano, Cortina d'Ampezzo, Lago di Garda, maybe even places like San Marino or Ljubljana.

There are TONS of options. You'll find something that works for you.

Iceland is indeed wonderful in August, BUT it is not cheap and most lodgings book 9-12 months in advance. That means the more reasonable places get booked up first, and you are left with the most expensive places, if there is even any availability. August is also high season there, so not as crowded as Italy etc, Reykjavik and the south coast get mobbed. We will be there again in August and are heading to the north to avoid that.

Thank you all for the thoughts.  I'm still leaning toward northern Italy.  Only wish I had a crystal ball to predict weather.  I've been dreaming of Italy all year, due to the influence of books and other things that I've been consuming this year. We like culture, cool architecture, views, natural beauty, food. I like museums as well but we don't spend a lot of time on this on family vacations. We generally rent cars when it makes more sense, but love public transportation when that makes more sense.

Katheryne and jules m - Poland is definitely on my future list.

bostonphil7 - Iceland has been on my list for a while, but our daughter may be going there later in the year.  Have not been to Alaska yet.  So true that August will be expensive in most places.

TexasTravelMom - I hadn't thought of the Baltics.

G3rryCee - We've been to Ireland, Netherlands and Belgium 20+ years ago without our daughter.
jphbucks - Wow, that was quite the trip, you covered a lot!

KCG - thanks for the suggestion.

HowlingMad - Do you not think Como and Dolomites will potentially be too hot?  That was my original plan, throwing in Venice and possibly Cinque Terre (we've been but our daughter hasn't).

mikliz97 - yes, I think Iceland is out at this point due to things booking up especially fast there.

Higher elevations or more northern latitudes or.........

Southern hemisphere - NZ, Aus, SA...

San Francisco, lol - mild or even chilly even in summer

edit to add: South America can be VERY reasonable and very welcoming

muget-- I agree, an Iceland trip would be better with more advance planning.