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When the daily average water temperature exceeds 32℃, the hatching rate and feeding rate of some warm water fish decrease with the increase of temperature, grow slowly or stop growing, and are easy to induce diseases. In summer, the water temperature in the fish pond is not always in the high temperature period. In this paper, based on the water and air temperature data of Fushun Aquaculture Meteorological Service Test Base from 2017 to 2019, the variation characteristics of water temperature in each layer of fish pond in summer were analyzed, and the prediction models of average and maximum water temperature on the sunny days were established by stepwise regression analysis. Results showed that the daily max. water temperature in each layer in summer occurs from 18:00 to 19:00, which lagged behind the temperature by 1-3 hours. The period when the water temperature ≥32℃ was mainly concentrated from 16:00 to 22:00, and the hourly average water temperature of each layer in this period was 32.9-33.1℃, 32.6-32.7℃ and 32.1-32.3℃, respectively. The water temperature of each layer fluctuated and rose with the temperature in summer, especially from mid-June to early-July, while the maximum values of temperature and water temperature appeared in late-July. The average number of days with water temperature ≥32℃ in summer was 23 days, accounting for a quarter of the whole summer, mainly from late July to mid-August. During this period, the daily average water temperature of each layer was 28.5-34.4℃, 28.2-34.1℃ and 27.9-33.9℃, respectively. The back substitution test in 2017-2018 and the forecast test in 2019 showed that the average absolute error of the model was 0.3-0.8℃, and the average relative error was within 2.6%, indicating that the model has good prediction effect and can be better applied to the prediction of fish pond water temperature in summer. [ABSTRACT FROM AUTHOR]

Based on the daily national meteorological data in spring in 2022, relationships between meteorological factors and agricultural production in China were analyzed using statistical methods. The results showed that the national average air temperature in spring in 2022 was 12.1Ž, which was the highest during the same period since 1961. The national average air temperature in the first ten days and the second ten days in March, and also in the first ten days in April, was abnormally higher than the same period from 1991 to 2020. The national average air temperature in the second ten days in May was obviously lower than the same period in the normal year. The year 2022 was a typical cold year in late spring. The national average precipitation in spring in 2022 was 154.0 mm, which was more than that in the same period in the normal year. In particular, the average precipitation in Sichuan in spring this year was the most since 1961. The national average sunshine was 649.2 hours, close to the same period in the normal year. The suitable sunshine and temperature, and also good soil moisture conditions were favorable for winter wheat growth with delayed sowing date in autumn in 2021 in Northern China, and the delayed-sowing winter wheat growing conditions continued to improve and upgrade in spring in 2022. The meteorological conditions in spring in 2022 were generally conducive to winter wheat growth and yield increase per hectare. The soil moisture and temperature conditions were suitable in most of the spring sowing areas, and the influence of phased low temperature was relatively light, which was conducive to the sowing and emergence of crops in spring. The progress of spring sowing was generally faster than that of the previous year. The seedlings growed well. It was sunny during most of winter wheat mature and harvest period in southern China, and the wheat harvest progressed well. But obvious drought in western Liaoning was unfavorable to spring sowing. In the late spring, heavy rainfall occurred in the east of Jianghan, the south of Jianghuai, the west of South China and the Southwest China. There were many rainy days and little sunshine in the south of Southwest China. At the end of spring, hot and dry weather appeared in some wheat areas in Eastern North China, Huang Huai. The bad weather had a certain negative impact on spring sowing and late grain filling of winter wheat in some of the above regions. [ABSTRACT FROM AUTHOR]