I never thought of this before, but yes Army units from Alaska would have a very limited amount of time to train in darkness since the best months weather wise to train have a lot of daylight:
Six hundred U.S. troops wrapped up a monthlong training rotation to South Korea Monday with something in short supply this time of year at their home station in Alaska — darkness.
Soldiers from the Fort Wainwright-based 1st Battalion, 5th Infantry Regiment “Bobcats” spent May living and training at the 3,390-acre Rodriguez Live Fire Range north of Seoul.
“We’re here to build our lethality,” battalion commander Lt. Col. R. Blake Lackey said Wednesday.
That includes being able to operate day and night, the latter being difficult in the Alaskan summer, he said.
“This time of year we’ll be training at 1:30 in the morning and it’s still daylight,” said Staff Sgt. Benjamin Moore, 34, a recon team leader with the battalion.
“When it’s dark in Alaska it’s winter and it’s pretty harsh,” the West Palm Beach, Fla., native added. “So it’s really difficult to get after some of the more basic and fundamental [requirements].”
The Korea rotation has taken the unit “to a higher level of readiness we didn’t think was possible,” Lackey said. [Stars & Stripes]
You can read the rest at the link.