Based on daily temperature (maximum

minimum and average) data of 153 meteorological stations

the spatial and temporal characteristics of extreme temperature events in the Huaihe River basin from 1961 to 2014 are analyzed from the perspective of trend and correlation

using statistical methods to calculate 26 extreme temperature indices. The regional response of climate change in the basin is further discussed by comparing with other regional temperature changes. The results are as follows: (1) The maximum

T

max

 and minimum

T

min

rise by a wide range of significant trend

the largest increase was 0.4 ℃ / 10a and 1.3 ℃ / 10a. Warm night days

summer days

hot wave spell duration indicator

and others in the Huaihe River basin as a whole are on the rise. The warm evenings with hot night index showed a trend of wide range increases significantly

with an increase of 6.3 d/10a and 7.1 d/10a. (2) Cold days

cold nights

frost days

icing days

cold spell duration indicator

cold wave spell duration indicator and frost spell duration indicator have significantly decreased by -2.3

-6.8

-10.0

-2.5

-10.0

 -7.3

-4.3 d/10a

respectively. (3) The diurnal temperature range in the Huaihe River basin is decreasing in general. The growing season length shows statistically significant increasing trends at rates of 7.6 d/10a

while the temperature index in the growing season length is slightly lower. (4) The extreme temperature indices of the Huaihe River basin have obvious differences in variation range

spatial distribution

time of mutation occurrence and correlation. In terms of change amplitude

the extreme cold index is greater than the extreme warmth index

and the night index is greater than the day index. On spatial distribution

the variation amplitude of these indices and significance test pass rate are greater in eastern region than in western region

and the increase of extreme warm indices in the southeast of the Huaihe River basin is far greater than in other areas. And extreme cold index mutations occur earlier than warm about 10 a. The most extreme temperature indices are correlated with the longitude

latitude and altitude. Particularly

the trend of main extreme temperature indices of the Huaihe River basin is consistent with regional and global scales.