Abstract: In order to evaluate the impact of temperature on crops more precisely, taking summer maize growth periods in different years in Hebei province as an example, the temperature suitability-degree of summer maize based on two time scales followed as the stroke of every hour of one single day and daily average temperature has been compared and analyzed by temperature suitability model. The results show that the probability of the difference values between 24h average daily temperature suitability-degree and daily temperature suitability-degree of the three national agricultural meteorological observation stations followed as Feixiang, Luancheng, and Zhuozhou for six years from 2015 to 2020, ≥0.6, ≥0.5, ≥0.4, ≥0.3, ≥0.2, ≥0.1 and ≥0.01 were 0.05%, 0.6%, 2.1%, 6.9%, 23.8%, 62.4% and 96.3% respectively, the proportions of coefficients of variation＞100%, 10%−100%, and＜10% were 0.2%, 50.0%, and 49.8%, respectively. There were moderate or above differences in 50.2% of the difference samples. The difference values between the 24h average daily temperature suitability-degree and daily temperature suitability-degree was quadratic with respect to the daily temperature range of the station on same day. If the daily temperature range was less than 12.5℃, 80.1% of the samples with a difference between the two would be within 0.2. If the daily temperature range was less than 8.4℃, 34.6% of the samples with a difference between the two would be within 0.1. In the case of continuous high temperature weather, the trend was consistent, and both timescales of temperature suitability-degree could reflect the effects of high temperature, with a 91.7% agreement of the test results. On consecutive days of low temperature, the 24h daily average temperature suitability-degree more accurately reflect the effect of low temperature, but the daily temperature suitability-degree does not respond to low temperature, the consistency between the two is only 30.0%.

Key words: Temperature suitability, Evaluation model, Hourly-scaled, Application