According to information posted on Kalmikovs' account on Facebook, the air temperature ranged from 15 to 19 degrees Celsius during the swim, while water temperature was a balmy 19 degrees Celsius.
The swimmer completed the crossing in 11 hours 13 minutes.
"I had a phenomenal team. You all did a great job... The swim was great, I really enjoyed it," he said.
"The last 40 meters were freezing, but overall it was a very good swim."
Kalmikovs, 46, participated in the 1996 and 2000 Olympics for Latvia. In Atlanta, he finished 13th in the 200-meter breaststroke, while in Sydney he was 17th in the same discipline. After his retirement, Kalmikov became a professional coach.
The first person to complete the cross-channel swim was famously Captain Matthew Webb, who became a national hero in the United Kingdom in 1875 as a result.
