Abstract: Water temperature is one of the most important environmental and ecological factors in freshwater pond aquaculture. To reveal the spatiotemporal variation characteristics of water temperature at different depths in freshwater ponds, this study used meteorological data and 11-layer pond water temperature observation data from the Guangdong Agricultural Meteorological Experimental Station from September 2022 to April 2024. Methods such as mathematical statistics and correlation analysis were adopted to analyze the variation rules of pond water temperature. Key meteorological factors for water temperature prediction under different weather conditions and high-impact weather events were selected, and the number of days suitable for fish growth was obtained by season. The results showed that: (1) In terms of monthly variation, the water temperature of each layer in the pond was basically consistent with the temperature change in the Pearl River Delta region. From February to August, the water temperature of each layer generally showed an upward trend, with the most significant increase in April and the peak in August; it began to decrease from September to December, with the most significant decrease in December and the valley value in January. (2) In terms of seasonal variation, the correlation coefficients between air temperature and water temperature of each layer within the same day all exceeded 0.90. The maximum temperature rise of water temperature in different water layers in each season followed the order: autumn > winter > summer > spring; the maximum temperature drop followed the order: winter > summer > spring > autumn. Among them, the water temperature variation in winter was the largest, ranging from-4.0 ℃ to 2.3 ℃. (3) On sunny days, water temperatures in spring, summer, and autumn were lower than air temperatures during the day but higher at night, a phenomenon most pronounced in spring; in winter, the water temperature was higher than the air temperature throughout the day, and the difference between the water temperature and the air temperature at night was the largest. On cloudy days, the temperature difference between water temperature and air temperature was small: the water temperature in spring was slightly lower than the air temperature, that in winter was slightly higher than the air temperature, and that in summer and autumn was lower than the air temperature during the day and higher than the air temperature at night. On rainy days, the water temperature in spring, summer and autumn was higher than the air temperature, and the variation range of water temperature was small; the temperature difference between water temperature and air temperature increased significantly during the concentrated precipitation period. (4) Under typhoon weather, water temperature correlated positively with air temperature and negatively with atmospheric pressure. During the passage of strong cold air masses, the water temperature showed a positive correlation with air temperature and a negative correlation with air pressure, and it took more than 10 days for the water temperature to return to the level before the temperature drop. During high-temperature weather, water temperature correlated significantly with the mean air temperature and pressure of the current day, previous day, and three days prior (correcting the original error regarding negative correlation). Under low-temperature and low-light weather, the water temperature had the same variation trend as the air temperature, and the variation range of humid-cold low-temperature and low-light weather was smaller than that of dry-cold low-temperature and low-light weather. (5) The annual suitable growth period of fish in the Pearl River Delta region reaches 351 days, and the distribution of the optimal growth period follows the order: summer (56 days) > autumn (42 days) > spring (38 days) > winter (13 days).