Temperature data are unavailable for most boll weevil overwintering habitats. As a result, ambient data often are used to estimate overwintering survival and emergence. In this study, relationship of ambient and overwintering habitat temperatures was determined for six habitats in the Rolling Plains of Texas. The amplitude of the daily temperature cycle in the leaf litter of each habitat was dampened compared with that recorded for ambient, with the average minimum daily leaf litter temperatures 3 to 6° C higher and the average maximum daily leaf litter temperatures 4 to 6°C lower than the average ambient temperatures. Multiple regressions of hourly and daily min-max leaf litter temperatures explained 93% of the variability, with ambient temperature and week of year being significant variables in all regressions. Except in mesquite-grass pasture, ambient temperatures overestimated positive degree-days (>6.1°C) experienced by overwintering weevils by 6-16%. All habitats had significantly fewer cumulative negative degree-days (<0.0°C) compared with that calculated for ambient.