first year grower, plz help

i was wondering around what time should i harvest this bad girl. i keep getting told the buds are going to explode out of nowhere but its getting late i dont want to accidentally freeze em waiting for this to happen. im in central cali 700ft above sea level. so theres your climate info. if anybody could help me it would be greatly appreciated.

wait till the hairs are 80% ready seeing your a medical user. the pics not that good but id say chop now.

Looks pretty ready..