The lowest temperature of 0.0 °C (32 °F) was recorded on 21 January 1934 Source: Wikipedia
The coolest temperature in Nigeria is about 15 - 17 degrees because the temperature never gets cold.
-26.3 i think :)
According to weather.com the coldest temperature ever recorded in Boston was -30F in 1946.
The lowest absolute temperature of Iran ever of -36 C was recorded in Saghez during the cold spell of 1969.