The dry and very warm weather continues for one more day with temperatures reaching into the 80s. This September continues to on the extreme side of warm. While you might be enjoying the long summer, if we were in this pattern during June or July, we’d be sizzling in the upper 90s to century mark. Today will be the 11th day at or above 80 degrees this month.

The shorter days and lower angle of the sun is preventing the ground and subsequently the air, from getting even warmer than it is in this pattern. It’s not unusual to have some 80 degree days right through September, but they are usually peppered between cooler ones. Typically, the last 80 degree occurs about September 22nd the other end of the warm season; the average date of the first 80 degree day is on May 1st. These are based on 30 year averages

Earlier Warmth
What’s really quite interesting is if you look at the average dates of the first and last 80 degree day in Portland over the past 15 years. In that short time span the first 80 degree day occurs on average 15 days earlier than it did in the period from 1970 to 2000. Since the turn of the century, 8 of the 16 years have seen the first 80 degree day occur before May. This is a remarkable shift and has tremendous impact on everything from spring skiing to lobstering.

Warmest September On Record Is Possible
Getting back to our current warm spell, presently September’s average 6.6 degrees above the 30 year mean. We are on pace to have the warmest September on record, but during the final 10 days the temperatures will be close to average or even a bit below. While it’s likely we end up near or at the top of warm Septembers, it won’t be as extreme as it is today.

Lack Of Rain
Depending on your lifestyle the lack of rain might not even be a factor. If you live in a condo or apartment with little outdoor space, the only indication we need rain might be you are watering your containers more often. However, if you have any size lawn, flower bed or vegetable garden you clearly have noticed it’s very dry. The shadows this time of year are longer, therefore the sun isn’t beating down on many areas as much and this helps plants make it through dry spells. However, if you have –over-seeded your lawn, or put in new trees and shrubs, it’s important you water them well until we do see significant widespread rain.

The weather maps in motion over the next two days show how high pressure (H) will move out to see as a cold front (blue line) moves through the area. Behind the front another area of high pressure (H) takes control of the weather for much of next week.

The second area of high pressure has Canadian air associated with it and therefore it is much cooler than the air we have been experiencing this month. It’s not going to be so chilly you’ll need the heat or anything like that, but it will feel more like the weather you’d expect for the autumnal equinox next week.

No Frost
It’s highly unlikely we see a frost in September anyway, but over the past 15 years the average date of the first frost has moved an entire week later. This means coastal Maine can continue to enjoy growing well into October in a typical season.