From February 26, 1927 to August 7, 1928, Canadian letters could receive air mail service in the United States if the U.S. mail rate of 10 cents per half ounce was prepaid in U.S. postage in addition to Canadian surface postage.
Vancouver to New York City, December2, 1927
2 cents surface letter rate to the United States + 10 cents U.S. air mail rate for half ounce
U.S. air mail stamp cancelled Blaine and Seattle RPO, December 3, 1927
New York receiver, December 5, 1927
Hamilton to Santa Rosa, Ca., September 8, 1927
2 cents surface letter rate to the United States + 10 cents U.S. air mail rate for half ounce
Chicago transit; the air mail stamp was cancelled with the Chicago Air Mail duplex killer
Toronto to Pasadena, November 24, 1927
1 oz. letter
2 cents surface letter rate to the United States + 20 cent U.S. air mail rate for 1 ounce
U.S. air mail stamp cancelled at Chicago
1 oz. letter
2 cents surface letter rate to the United States + 20 cent U.S. air mail rate for 1 ounce
U.S. air mail stamp cancelled at Chicago
B. Air Mail Service in Canada and the United States
The rates shown in this section are for the first ounce.
1. August 24, 1928 - June 30, 1931 : 5 cents
The first air mail rate to the United States was 5 cents for the first ounce and 10 cents for each additional ounce.
Vancouver to Oakland, March 27, 1929
5 cents air mail letter rate to the United States
Montreal to Fontana, Ca., November 24, 1931
6 cents paying 5 cents United States air mail letter rate + 1 cent War Tax
Victoria to Duarte, Ca., February 6, 1933
8 cents paying 7 cents United States air mail letter rate + 1 cent War Tax
Regina to Wooster, Ohio, March 9, 1934
8 cents paying 7 cents United States air mail letter rate + 1 cent War Tax
Ottawa to Los Angeles, April 25, 1936
6 cents paying 5 cents United States air mail letter rate + 1 cent War Tax
Toronto to New York, June 4, 1940
6 cents paying 5 cents United States air mail letter rate + 1 cent War Tax
Toronto to Cambridge, Mass., June 30, 1941
6 cents paying 5 cents United States air mail letter rate + 1 cent War Tax
Ottawa to San Francisco, October 2, 1942
6 cents paying 5 cents United States air mail letter rate + 1 cent War Tax
Ottawa to Washington,March 9, 1949
7 cents paying 5 cents United States air mail letter rate + 2 cents War Tax
5 cents air mail letter rate to the United States
2. July 1, 1931 - July 31, 1932: War Tax
A War Tax of 1 cent was added to the 1st ounce air mail letter weight on July 1, 1931 for a total of 6 cents. The rate for each additional ounce was 10 cents.
6 cents paying 5 cents United States air mail letter rate + 1 cent War Tax
3. August 1, 1932- June 30, 1934 : Rate Increase
The air mail letter rate with War Tax increased from 6 cents to 8 cents on August 1, 1932. The rate for each additional ounce was 13 cents.
8 cents paying 7 cents United States air mail letter rate + 1 cent War Tax
8 cents paying 7 cents United States air mail letter rate + 1 cent War Tax
4. July 1, 1934 - March 31, 1943 : Rate Reduction
The air mail letter rate with War Tax decreased from 8 cents to 6 cents on July 1, 1934. The rate for each additional ounce was 6 cents.
6 cents paying 5 cents United States air mail letter rate + 1 cent War Tax
6 cents paying 5 cents United States air mail letter rate + 1 cent War Tax
6 cents paying 5 cents United States air mail letter rate + 1 cent War Tax
6 cents paying 5 cents United States air mail letter rate + 1 cent War Tax
5. April 1, 1943 - June 30, 1951 : War Tax Increase
The War Tax was increased from 1 cent to 2 cents for the 1st ounce for a total of 7 cents. The rate for each additional ounce was 6 cents. On November 1, 1946, the rate for each additional ounce was reduced to 5 cents.
Vancouver (Censored Cancel) to New York, August 14, 1944
7 cents paying 5 cents United States air mail letter rate + 2 cents War Tax
Montreal to New York, February 4, 1945
7 cents paying 5 cents United States air mail letter rate + 2 cents War Tax
7 cents paying 5 cents United States air mail letter rate + 2 cents War Tax
Vancouver to Cuba, New York, February 11, 1948
7 cents paying 5 cents United States air mail letter rate + 2 cents War Tax
Montreal to East Aurora, July 13, 1950
7 cents paying 5 cents United States air mail letter rate + 2 cents War Tax
6. July 1, 1951 - July 14, 1964 : 7 cents rate (War Tax incorporated into rate)
The effective rate was unchanged but the 2 cents War Tax became incorporated into the air mail postage rate.
Gander to Fort Worth, September 27, 1951
7 cents air mail letter rate to the United States
7 cents air mail rate to the United States
7 cents air mail letter rate to the United States
Winnipeg to Beltsville, Md., August 22, 1956
7 cents air mail letter rate to the United States
7 cents air mail letter rate to the United States
7 cents air mail letter rate to the United States
7 cents air mail letter rate to the United States
7. July 15, 1964 - October 31, 1968 : Rate Increase
The air mail letter rate to the United States increased from 7 cents to 8 cents for the 1st ounce. The rate for each additional ounce was 6 cents.
8 cents air mail letter rate to the United States
8 cents air mail letter rate to the United States
London to Delray Beach. Fl., February 13, 1967
8 cents letter rate to the United States
8. November 1, 1968 - February 29, 1976 : Rate Increase
The air mail rate to the United States increased from 8 cents to 10 cents for the 1st ounce and 10 cents for each additional ounce.
Peterborough to Creve Coeur, Mo., August 31, 1973
10 cents air mail letter rate to the United States
Toronto to Guam, April 22, 1972
10 cents air mail letter rate to the United States applied to U.S. possessions
Red Deer to Port Chester, N.Y., April 28, 1975
10 cents per ounce air mail letter rate to the United States
9. March 1, 1976 : All-Up Letter Rate to the U.S.
On
March 1, 1976, the two letter rates to the United States, surface and air mail, were replaced with a single "all-up" rate of 10 cents per ounce.
Richmond, B.C., to Jackson, Miss., January 17, 1977
10 cents all-up letter rate to the United States
The elimination of the surface letter rate to the United States which was the same as the domestic rate created initial confusion as evidenced by the shortpaid covers shown below:
Aylmer West to Portland, Oregon, April 22 1976 (7:00 am cancellation)
10 cents first ounce all-up letter rate to the United States
8 cents affixed originally, thus shortpaid 2 cents
The letter was returned to the sender for additional postage:
2 cents added (Macdonald definitives) and cancelled at Aylmer West, April 22 1976 (10 p.m. cancellation)
Toronto to Youngstown, Ohio, April 15, 1976
10 cents all-up letter rate to the United States
Shortpaid 2 cents and taxed 4 cents due
4 cents Youngstown postage due meter tape affixed
See Canadian Letter Rates to the United States : 1868 to the present for U.S. rates from 1976 to the present.