Early on May 17th a strong cold front pushed through the region, allowing for an unseasonably cold and dry Canadian airmass to settle in across the region.  Gusty winds during the afternoon quickly diminished during the evening as surface high pressure crested over the region.  The cold airmass, clear skies and no winds allowed for perfect radiational cooling temperatures.  Temperatures quickly dropped through the night with widespread sub-freezing conditions all the way to the coast.  Many areas dropped down into the upper 20s, with the coldest conditions across low-lying valley locations.  Leave-out had already occurred away from the mountains with agriculture impacts reported to berry and fruit tree crops.

Frost/Freeze in BELKNAP, NEW HAMPSHIRE
From 18-MAY-23 02:00:00 to 18-MAY-23 07:00:00 (EST-5)
Property damage: 0.00K
Reported by: Broadcast Media

A hard freeze impacted the region shortly after midnight on May 18th with widespread sub-freezing temperatures. Temperatures ranged from freezing to the mid-20s. Tilton reported a low of 28 degrees. The temperatures were some of the coldest this late in spring in over the past 30 years based on official records. The hard freeze impacted blooming fruit trees and berries the most. The hardest hit orchards were those at lower elevations in valleys with less impacts at orchards located at slightly higher elevations on hills. There were reports of flower mortality rate as high as 90% in some areas. In addition, leaf kill was prevalent with some oak species due to these tree species being more vulnerable to freezing.

Frost/Freeze in SOUTHERN CARROLL, NEW HAMPSHIRE
From 18-MAY-23 02:00:00 to 18-MAY-23 07:00:00 (EST-5)
Property damage: 0.00K
Reported by: Broadcast Media

A hard freeze impacted the region shortly after midnight on May 18th with widespread sub-freezing temperatures. Temperatures ranged from freezing to the mid-20s. Moultonborough reported a low of 26 degrees. The temperatures were some of the coldest this late in spring in over the past 30 years based on official records. The hard freeze impacted blooming fruit trees and berries the most. The hardest hit orchards were those at lower elevations in valleys with less impacts at orchards located at slightly higher elevations on hills. There were reports of flower mortality rate as high as 90% in some areas. In addition, leaf kill was prevalent with some oak species due to these tree species being more vulnerable to freezing.

Frost/Freeze in CHESHIRE, NEW HAMPSHIRE
From 18-MAY-23 02:00:00 to 18-MAY-23 07:00:00 (EST-5)
Property damage: 0.00K
Reported by: AWOS

A hard freeze impacted the region shortly after midnight on May 18th with widespread sub-freezing temperatures. Temperatures ranged from freezing to the mid-20s. Keene reported a low of 25 degrees. The temperatures were some of the coldest this late in spring in over the past 30 years based on official records. The hard freeze impacted blooming fruit trees and berries the most. The hardest hit orchards were those at lower elevations in valleys with less impacts at orchards located at slightly higher elevations on hills. There were reports of flower mortality rate as high as 90% in some areas. In addition, leaf kill was prevalent with some oak species due to these tree species being more vulnerable to freezing.

Frost/Freeze in SOUTHERN GRAFTON, NEW HAMPSHIRE
From 18-MAY-23 02:00:00 to 18-MAY-23 07:00:00 (EST-5)
Property damage: 0.00K
Reported by: AWOS

A hard freeze impacted the region shortly after midnight on May 18th with widespread sub-freezing temperatures. Temperatures ranged from freezing to the mid-20s. Plymouth reported a low of 26 degrees. The temperatures were some of the coldest this late in spring in over the past 30 years based on official records. The hard freeze impacted blooming fruit trees and berries the most. The hardest hit orchards were those at lower elevations in valleys with less impacts at orchards located at slightly higher elevations on hills. There were reports of flower mortality rate as high as 90% in some areas. In addition, leaf kill was prevalent with some oak species due to these tree species being more vulnerable to freezing.

Frost/Freeze in EASTERN HILLSBOROUGH, NEW HAMPSHIRE
From 18-MAY-23 02:00:00 to 18-MAY-23 07:00:00 (EST-5)
Property damage: 0.00K
Reported by: AWOS

A hard freeze impacted the region shortly after midnight on May 18th with widespread sub-freezing temperatures. Temperatures ranged from freezing to the mid-20s. Nashua reported a low of 27 degrees. The temperatures were some of the coldest this late in spring in over the past 30 years based on official records. The hard freeze impacted blooming fruit trees and berries the most. The hardest hit orchards were those at lower elevations in valleys with less impacts at orchards located at slightly higher elevations on hills. There were reports of flower mortality rate as high as 90% in some areas. In addition, leaf kill was prevalent with some oak species due to these tree species being more vulnerable to freezing.

Frost/Freeze in WESTERN AND CENTRAL HILLSBOROUGH, NEW HAMPSHIRE
From 18-MAY-23 02:00:00 to 18-MAY-23 07:00:00 (EST-5)
Property damage: 0.00K
Reported by: AWOS

A hard freeze impacted the region shortly after midnight on May 18th with widespread sub-freezing temperatures. Temperatures ranged from freezing to the mid-20s. Peterborough reported a low of 29 degrees. The temperatures were some of the coldest this late in spring in over the past 30 years based on official records. The hard freeze impacted blooming fruit trees and berries the most. The hardest hit orchards were those at lower elevations in valleys with less impacts at orchards located at slightly higher elevations on hills. There were reports of flower mortality rate as high as 90% in some areas. In addition, leaf kill was prevalent with some oak species due to these tree species being more vulnerable to freezing.

Frost/Freeze in MERRIMACK, NEW HAMPSHIRE
From 18-MAY-23 02:00:00 to 18-MAY-23 07:00:00 (EST-5)
Property damage: 0.00K
Reported by: AWOS

A hard freeze impacted the region shortly after midnight on May 18th with widespread sub-freezing temperatures. Temperatures ranged from freezing to the mid-20s. Concord reported a low of 25 degrees. The temperatures were some of the coldest this late in spring in over the past 30 years based on official records. The hard freeze impacted blooming fruit trees and berries the most. The hardest hit orchards were those at lower elevations in valleys with less impacts at orchards located at slightly higher elevations on hills. There were reports of flower mortality rate as high as 90% in some areas. In addition, leaf kill was prevalent with some oak species due to these tree species being more vulnerable to freezing.

Frost/Freeze in INTERIOR ROCKINGHAM, NEW HAMPSHIRE
From 18-MAY-23 02:00:00 to 18-MAY-23 07:00:00 (EST-5)
Property damage: 0.00K
Reported by: COOP Observer

A hard freeze impacted the region shortly after midnight on May 18th with widespread sub-freezing temperatures. Temperatures ranged from freezing to the mid-20s. Epping reported a low of 27 degrees. The temperatures were some of the coldest this late in spring in over the past 30 years based on official records. The hard freeze impacted blooming fruit trees and berries the most. The hardest hit orchards were those at lower elevations in valleys with less impacts at orchards located at slightly higher elevations on hills. There were reports of flower mortality rate as high as 90% in some areas. In addition, leaf kill was prevalent with some oak species due to these tree species being more vulnerable to freezing.

Frost/Freeze in STRAFFORD, NEW HAMPSHIRE
From 18-MAY-23 02:00:00 to 18-MAY-23 07:00:00 (EST-5)
Property damage: 0.00K
Reported by: Broadcast Media

A hard freeze impacted the region shortly after midnight on May 18th with widespread sub-freezing temperatures. Temperatures ranged from freezing to the upper-20s. Dover reported a low of 28 degrees. The temperatures were some of the coldest this late in spring in over the past 30 years based on official records. The hard freeze impacted blooming fruit trees and berries the most. The hardest hit orchards were those at lower elevations in valleys with less impacts at orchards located at slightly higher elevations on hills. There were reports of flower mortality rate as high as 90% in some areas. In addition, leaf kill was prevalent with some oak species due to these tree species being more vulnerable to freezing.

Frost/Freeze in SULLIVAN, NEW HAMPSHIRE
From 18-MAY-23 02:00:00 to 18-MAY-23 07:00:00 (EST-5)
Property damage: 0.00K
Reported by: Mesonet

A hard freeze impacted the region shortly after midnight on May 18th with widespread sub-freezing temperatures. Temperatures ranged from freezing to the mid-20s. Sunapee reported a low of 26 degrees. The temperatures were some of the coldest this late in spring in over the past 30 years based on official records. The hard freeze impacted blooming fruit trees and berries the most. The hardest hit orchards were those at lower elevations in valleys with less impacts at orchards located at slightly higher elevations on hills. There were reports of flower mortality rate as high as 90% in some areas. In addition, leaf kill was prevalent with some oak species due to these tree species being more vulnerable to freezing.