The last two winter's I reach 21F. The first year 80F one day the next 21F. This year we had a week of cold  weather before the 21F freeze. First year -Kishu 80% was defoliated, but still made a light crop. Fair sized NZ lemonade killed, this was the only citrus I lost. This year- Kishu 15% defoliated, looking good now.

Flooding injury is highly probable if the root zone is saturated for three or more days during the summer when soil temperatures (86°F-95°F) are relatively high.  Flooding during the cooler December–March period can be tolerated for several weeks at low soil temperatures (<60°F).
 
Full article
http://www.crec.ifas.ufl.edu/extension/trade_journals/2015/2015_June_flooding.pdf

In the article it claims that citrus in moving water has allot less stress. Maybe that's my case. My trees have been flooded many times over the last twenty years in hot to very hot weather with very little problems. We had a back to back floods a few years ago and the trees were underwater for about two weeks in the middle of the summer. My property is river front and when it floods the river is really flowing by.

Ilya-I looked at your post on your bloomsweet. Yours seems to be different from mine and other bloomsweet I have handled. Most of mine have a somewhat of a "teardrop" shape to them, color wise mine are very light colored, and mine have lots of seeds.

Let me look for some bloomsweet seeds this weekend. I had a 22 deg.freeze and all my bloomsweet fruit froze and dropped to the ground. There was a ton of fruit on the ground a couple of weeks ago, I bet I can find a few seeds.