Retalhuleu, Guatemala experiences mild temperatures year-round with minimal seasonal variation. Daytime highs often reach the mid-to-high 30s Celsius during the dry season, which typically begins in March and lasts until October. Nighttime lows rarely drop below 0°C even in winter months, and average around 7-10°C from June to September. The cooler months are December and January, with temperatures ranging from 0-34°C, while the warmer months are April and May, with highs reaching up to 36°C. Overall, Retalhuleu's climate is characterized by warm days and mild nights, with little precipitation throughout most of the year.