As Smitty1 says, AW is much better than WR. A 2013 lens catalogue described these as:
AW lenses provide maximum weather-resistant and dustproof performance preventing the intrusion of drizzle and dust into the lens barrel.
The next category of “all weather” PENTAX lenses is designated as WR or weather-resistant. These affordable lenses utilize a simplified weather-resistant construction, making it more difficult for water to enter the lens and are designed to repel a light splash of water.
Started out doing photography at the age of 6 using an uncle's old 1940 kodak brownie box camera. At 15 years of age, I decided to buy my very own 1975 Praktica SLR camera. I now shoot with a Nikon D850. I do unpaid TFP and commercial paid work.