Positive rate From Australia, joined Sep 2001, 2143 posts, RR: 1
Reply 1, posted (12 years 7 months 1 week 5 days 20 hours ago) and read 1566 times:
From personal observations i'd say contrails seem to be more prevalent during the summer months. During winter- even when we don't have cloud cover i very rarely see any contrails at all, despite there being an airway almost directly over my house. During summer though when the air conditions are calmer i normally see about 5 a day, they are really thick long bright ones.