Best time to travel Poland

September has better weather and days are longer.

Thanks. September it is.

When booking directly with the hotel, is it best to fax credit cards info?

You can choose one of four options to convey your credit card number to the hotel:
1) send the entire number via email. Some consider this too risky.
2) send the number broken unto portions in separate emails.
3) call the hotel directly to give them the entire number.
4) You could also fax, which will also cost you the same as a phone call.

I'll be there in early October. Less tourists!

I usually travel in October as tourists are fewer but can the weather turn ugly in October?

You can check weather on timeanddate.com. I think early October might be a bit cool in Poland, we are traveling in the spring when it will also be sort of cool. Of course you never know about the weather but you can look at averages. I usually book through booking.com because booking direct, have found hotels to be unresponsive and unspecific about cancellation policies. Booking.com lays it all out for you and cancellation is automated, should the need arrive. If you booked direct, personally I have never worried about emailing credit card numbers. I don't think you have to worry quite as much about tourist mobs in Poland compared to say, London or Rome, but I have not been there yet so not sure about that.

I usually travel in October as tourists are fewer but can the weather
turn ugly in October?

Yes. It can even turn ugly mid-September and on. The patterns have been so wacky over the past few years that it's impossible to predict. Early September should be fine, but I would definitely not go the last two weeks of October (unless you want to deal with rain, cold, etc). If you have to go in October, go as early as possible. There are no major tourist issues except maybe in Krakow, especially compared to other European countries.

May is also a beautiful time to be there.

I've never booked any hotel that required faxing credit card info. I often use booking.com and it seems to work just fine in holding the rooms via credit card and secure server.

The average temperature for Krakow during the month of October is 54 degrees Fahrenheit (12 degrees Celcius) while the average high is 61 (16 Celcius) and the average low is 46 (8 Celcius). Perfect for me and the wife.

I was in Poland last October (Warsaw and vicinity) and it was cool and rainy. Definitely wish I had taken a heavier jacket. I was there in early to mid October.