Studying the impact of temperature on evaporation observations at meteorological stations is of great significance for climate change research and the assessment of meteorological drought disasters. An analysis of the diurnal variation characteristics of hourly evaporation and temperature data from the Anqing Meteorological Station's automatic station from April to November 2017 shows that the diurnal variation patterns of hourly evaporation and temperature are similar, both exhibiting a high-low trend, with the peak hourly evaporation occurring 3 hours later than that of temperature. Through experimental research on water temperature in evaporation measurements at the Anqing Meteorological Station, it was found that after sunrise, the water temperature in the E601B evaporation pan rises, leading to an increase in volume. Combined with the influence of the operational software's automatic evaporation algorithm, this results in smaller measured hourly evaporation values in the morning and larger values from afternoon to evening on clear days. Analysis of data from two warming weather events showed that daily evaporation measurements were underestimated by 7~26%, while measurements from two systematic cooling processes were overestimated by 15~19%. A comprehensive correlation analysis of hourly evaporation and related meteorological factors at the Anqing and Taihu automatic stations in southwestern Anhui indicates that thermal factors are the primary drivers of hourly evaporation variation. Shallow ground temperatures at 10–20 cm have the most significant impact on hourly evaporation, with the 15 cm ground temperature showing the strongest correlation with hourly evaporation.