I suppose one could describe Texas summers this way—and be totally accurate.

inimical (in·im·i·cal): / i NIM i kuhl /
adjective

(1) adverse in effect; unfavorable; harmful; injurious
(2) hostile; unfriendly

[From Late Latin inimicalis from Latin inimicus meaning “unfriendly, hostile,” from in- (“not”) + amicus (“friend”).]

Usage: His gaze was both inimical and cold, a reminder that we had not yet overcome our differences.