There's some mention along with some photos in some scattered topics about this fashion, the wearing of Field Jackets worn with Khaki Uniforms in warm weather on rainy drizzly days Army Wide, a curious Uniform of the Day right, like why not wear the Raincoat, either the Taupe one or the one that replaced it, the Sage Green one.

 

These are troops of the 14th Armored Cavalry Regiment West Germany summer of 1968.

Yes, the wear of the field coat with khakis was a uniform choice when the weather called for it. The Army used to have specific "seasons" for the wear of certain uniforms.  As Summer ended and Fall began, it coud get chilly and the field coat was needed.

Here's one more sighting, this time with reservists of the old 77th Infantry division in NYC in the early 1960s.

I'd guess it's because that long trench coat is a pretty unwieldy piece of gear.  Trench coats made sense in the trenches when soldiers were spending a lot of time on their feet or marching, but post WWII with everyone traveling by car or truck or some other type of transportation, that long coat just gets in the way.  

 

The top picture also appears to be maybe some kind of ceremony?  They're wearing bloused boots, helmets and pistol belts so the field jacket makes more sense than the trench coat.  Sergeant on the far right is holding what may be orders and all the soldiers in the front row have medals pinned to their jackets, so maybe some kind of award ceremony.  

 

BTW when I came in the Army had replaced the trench coat with a shorter black all weather jacket that was ugly and universally hated.  I think it was called the all weather coat, and it looked like a black trash bag.  Supposed to only be for wear with the class A or B uniform, but I recall seeing some trainees at Fort Benning wearing it over green (pickle suit) fatigues because they had not yet inprocessed and hadn't been issued any rain gear (poncho or rain jacket.)  It was too hot for a field jacket so the black all-weather coat was the only piece of actual "rain gear" they would have had.  

 

They eliminated khakis right after I came in so I was never issued any.  What was the rule on khakis, was there a firm date (like May 1st to November 1st) for khakis as opposed to greens or was it left to each command to have a date when khakis were no longer authorized for the season?  I remember a similar rule regarding rolled up sleeves during the BDU era.  I think it was May 15 to November 15th at Fort Bragg in the 1990's but I can't remember for sure.  

Well I can tell you in the 80-82 period and no doubt back into the 70s that the Sage Green Raincoat was indeed worn on several occasions as an outer garment in inclement weather with fatigues in garrison, worn with the Gold Rank pins, worn instead of the field jacket, this would be in warmer weather, Spring and early Fall.

On 10/18/2022 at 11:22 PM, patches said:

Well I can tell you in the 80-82 period and no doubt back into the 70s that the Sage Green Raincoat was indeed worn on several occasions as an outer garment in inclement weather with fatigues in garrison, worn with the Gold Rank pins, worn instead of the field jacket, this would be in warmer weather, Spring and early Fall.

 

Garrison being the key word there.

A little after the fact, but I'll add to the post.  My time on active was '72-'78.  During those years khaki were in vogue as was the tropical wear "TW's if you wanted to purchase them.  The sage green or grayish raincoat was worn with the khakis, TW's and OG107 fatigues & the OG507 "perma press" fatigues (the 507's were a purchase item if so desired.   The field jacket M65 and for those old timers or stract troops & drill sergeants back in those days the older M51 field jacket was worn also worn with class "B" and the fatigues.   The M51 was well liked for appearance because it looked really great all starched, impressive.  I'm not sure when the official wear-out date was for the M51, but I was still wearing one off and on in '78.   The other neat jacket worn with just the class "B" only was the sage green or grayish windbreaker I believe the color shade was the AG274, possibly the same as the raincoat.  The windbreaker was another purchase item if you so desired to have one.  Both the raincoat and windbreaker could be worn with civilian attire providing all the military insignia was removed.

 

Another little item dealing with the windbreaker, especially if your duty uniform was the class B and working a swing or midnight shift and it being a bit chilly out, one could take the nylon field jacket liner (preferably an extra one you purchased at clothing sales), adjust the length by pinning or alteration, sew some buttons on the inside of the windbreaker to match the existing liner button-holes and wear it under the windbreaker.  Worked very well.