Abstract: The trends in daily frequency of maximum and minimum temperatures over the last 44 years were analyzed using the daily maximum and minimum temperature data from 1961 to 2004 in Ningxia, by classifying the temperatures into 38 levels. It was found that daily frequency of maximum temperature below 0℃ decreased while that over 30℃ increased. The annual average minimum temperature increased, meanwhile the daily frequency of extremely low temperature also increased by 350%-275% in 1991-2004 relative to 1961-1990. Therefore, the extreme trends of temperature are obvious in Ningxia.

Key words: climate change, frequency, maximum temperature, minimum temperature, Ningxia