Washington: Today - Variably cloudy, chance of rain, high in the upper 60s, low near 40. The chance of rain is 80 per cent today and 50 per cent tonight. Friday - Variably cloudy, high in mid 50s.

Maryland and Virginia: Rain, highs from the upper 50s to near 70, lows from the low 30s to the low 40s. Friday - Variably cloudy, high from the 40s to the upper 50s.

Lower Potomac and Chesapeake Bay: Today - Rain with visibility of more than 5 miles, except for less than 2 miles in rain. Wind will be from the south at from 15 to 25 knots today, but wind will be shifting at from 10 to 15 knots tonight.

West Virginia: Today - Rain, highs in the 60s, lows in the 30s Friday - Partly cloudy, highs in the 50s.

Extended Area Forecast for Saturday through Friday: Partly cloudy through the period with a chance of showers in the mountains. Highs will be from the mid 40s to the upper 50s, lows from the mid 20s to the mid 30s. Normal Washington temperatures for the period are a high of 49 and a low of 30.

The National Weather Forecast for today - Showers and Thunderstrom will fall over the Atlantic and eastern Gulf coasts through the Ohio Valley and into the Great Lakes. There will be snow in Maine, the western Great Lakes, Minnesota and the eastern Dakotas Rain, with snow in the mountains, will continue from the northern and central Pacific Coast into the northern and central plateau and northern Rookies. The remainder of the nation will be sunny to partly cloudy. It will be colder in the lower and middle Mississippi Valley and western Ohio Valley. There will be little temperature change elsewhere.

Almanac data for today - Sun rises 6:48 a.m., sets 5:55 p.m.; moon rises 10:11 a.m. Tides: High 12:14 p.m., low 6:48 a.m. and 7:21 p.m. High and low tides at the following points can be obtained by subtracting the hours indicated from the tides above. Annapolis (3 1/4); Bloody Point Lighthouse (4 1/2); Deale, Md. (4 1/2); Colonial Beach (6); Norfolk (1 1/2); Virginia Beach (1); Solomon's Island (6 1/2); Point Lookout (7).

The Council of Governments' Air Quality Index for yesterday showed the high reading in the Washington area during the 2 p.m. to 3 p.m. period was 25 for the pollutant, photochemical oxidants. Index values between 25 and 40 indicate fair air quality. When the index exceeds 100 the air becomes hazardous and persons with lung, heart and eye problems should restrict their activity. The forecast for today indicates the air quality will improve.

The National Weather Service forecasts that the Potomac River stage at Little Falls will be near 3.5 feet.

Washington data at 7 p.m. (EST) yesterday: Highest temperature since 7 a.m. yesterday, 72 degrees at 2:40 p.m. Lowest temperature a.m. Deficiency of temperature since Feb. 1, 18 degrees. Deficiency of temperature since Jan. 1 322 degrees. Record high temperature for today, 70 degrees in 1975. Record low temperature for today, 1 degrees in 1873. Relative humidity: Maximum, 70 per cent at 5 a.m. Minimum, 24 per cent at 4 p.m. Deficiency of precipitation since Feb. 1, 1.93 inches. Deficiency of precipitation since Jan. 1, 3-0s inches. Highest observed wind since 7 a.m. 18 miles per hour from the south at 3 p.m. Peak qust since 7 a.m., 29 miles per hour from the south at 2:58 p.m. Local Temp., Humidity(TABLE) time(COLUMN)T.(COLUMN)H. 12 mid.(COLUMN)48.(COLUMN)52 1 a.m.(COLUMN)49(COLUMN)50 2 a.m.(COLUMN)45(COLUMN)53 3 a.m.(COLUMN)42(COLUMN)65 4 a.m.(COLUMN)42(COLUMN)65 5 a.m.(COLUMN)41(COLUMN)70 6 a.m.(COLUMN)41(COLUMN)70 7 a.m.(COLUMN)42(COLUMN)67 8 a.m.(COLUMN)45(COLUMN)60 9 a.m.(COLUMN)50(COLUMN)50 10 a.m.(COLUMN)55(COLUMN)44 11 a.m.(COLUMN)60(COLUMN)36 12 noon(COLUMN)61(COLUMN)39 1 p.m.(COLUMN)66(COLUMN)34 2 p.m.(COLUMN)70(COLUMN)32 3 p.m.(COLUMN)72(COLUMN)26 4 p.m.(COLUMN)72(COLUMN)24 5 p.m.(COLUMN)70(COLUMN)25 6 p.m.(COLUMN)61(COLUMN)28 7 p.m.(COLUMN)58(COLUMN)37(END TABLE) Temperatures ending 8 a.m. (EST) yesterday:(TABLE) City(COLUMN)H.(COLUMN)L. Albany(COLUMN)33(COLUMN)23 Albuquerque(COLUMN)61(COLUMN)30 Marillo(COLUMN)79(COLUMN)35 Anchorage(COLUMN)41(COLUMN)30 Asheville(COLUMN)66(COLUMN)43 Atlanta(COLUMN)67(COLUMN)38 Atlantic City(COLUMN)46(COLUMN)40 Austin(COLUMN)74(COLUMN)64 Baltimore(COLUMN)61(COLUMN)43 Billings(COLUMN)43(COLUMN)30 Birmingham(COLUMN)72(COLUMN)55 Bismarck(COLUMN)37(COLUMN)30 Boise(COLUMN)47(COLUMN)28 Boston(COLUMN)37(COLUMN)29 Brownsville(COLUMN)78(COLUMN)68 Bufflo(COLUMN)42(COLUMN)28 Burlington(COLUMN)26(COLUMN)13 Casper(COLUMN)43(COLUMN)27 Charleston, S.C.(COLUMN)59(COLUMN)44 Charleston, W.V.(COLUMN)63(COLUMN)44 Charlotte(COLUMN)67(COLUMN)36 Cheyenne(COLUMN)44(COLUMN)26 Chicago(COLUMN)55(COLUMN)39 Cincinnati(COLUMN)61(COLUMN)46 Cleveland(COLUMN)49(COLUMN)42 Columbia, S.C.(COLUMN)70(COLUMN)33 Columbus(COLUMN)57(COLUMN)41 Dal.-Ft. Worth(COLUMN)72(COLUMN)57 Dayton(COLUMN)58(COLUMN)46 Denver(COLUMN)55(COLUMN)36 Des Moines(COLUMN)65(COLUMN)52 Detroit(COLUMN)49(COLUMN)34 Duluth(COLUMN)24(COLUMN)18 El Paso(COLUMN)77(COLUMN)45 Fairbanks(COLUMN)27(COLUMN)19 Fargo(COLUMN)39(COLUMN)25 Flagstaff(COLUMN)45(COLUMN)21 Great Falls(COLUMN)49(COLUMN)32 Hartford(COLUMN)36(COLUMN)23 Helena(COLUMN)45(COLUMN)33 Honolulu(COLUMN)85(COLUMN)75 Houston(COLUMN)71(COLUMN)67 Indianapolis(COLUMN)63(COLUMN)43 Jackson, Miss.(COLUMN)74(COLUMN)64 Juneau(COLUMN)43(COLUMN)33 Kansas City(COLUMN)64(COLUMN)52 Las Vegas(COLUMN)63(COLUMN)38 Little Rock(COLUMN)68(COLUMN)62 Los Angeles(COLUMN)71(COLUMN)54 Louisvile(COLUMN)70(COLUMN)53 Memphis(COLUMN)73(COLUMN)54 Miami Beach(COLUMN)68(COLUMN)67 Midland-Odessa(COLUMN)86(COLUMN)46 Milwaukee(COLUMN)37(COLUMN)31 Mpls.-St. Paul(COLUMN)41(COLUMN)32 Nashville(COLUMN)71(COLUMN)58 New Orleans(COLUMN)76(COLUMN)65 New York(COLUMN)46(COLUMN)43 Norfolk(COLUMN)59(COLUMN)37 North Platte(COLUMN)55(COLUMN)32 Oklahoma City(COLUMN)77(COLUMN)49 Omaha(COLUMN)62(COLUMN)52 Orlando(COLUMN)71(COLUMN)47 Philadelphia(COLUMN)52(COLUMN)36 Philadelphia(COLUMN)52(COLUMN)36 Phoenix(COLUMN)75(COLUMN)48 Pittsburgh(COLUMN)53(COLUMN)40 Portland, Me.(COLUMN)31(COLUMN)14 Portland, Ore.(COLUMN)47(COLUMN)32 Providence(COLUMN)39(COLUMN)28 Raleigh(COLUMN)65(COLUMN)35 Rapid City(COLUMN)43(COLUMN)32 Reno(COLUMN)44(COLUMN)33 Richmond(COLUMN)66(COLUMN)40 St. Louis(COLUMN)74(COLUMN)61 St. Prbg. - Tampa(COLUMN)69(COLUMN)52 Salt Lake City(COLUMN)39(COLUMN)33 San Antonio(COLUMN)76(COLUMN)60 San Diego(COLUMN)68(COLUMN)57 San Francisco(COLUMN)58(COLUMN)48 San Juan(COLUMN)85(COLUMN)70 St. Ste. Marie(COLUMN)31(COLUMN)08 Seattle(COLUMN)52(COLUMN)39 Shreveport(COLUMN)74(COLUMN)68 Sioux Falls(COLUMN)53(COLUMN)35 Spokane(COLUMN)48(COLUMN)30 Syracuse(COLUMN)42(COLUMN)21 Tucson(COLUMN)71(COLUMN)43 Tulsa(COLUMN)76(COLUMN)52 Washington(COLUMN)63(COLUMN)40 Witchita(COLUMN)74(COLUMN)44(END TABLE) Temperatures Abroad Yesterday(TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)Temp. Aberdeen(COLUMN)clear(COLUMN)1 p.m.(COLUMN)39 AMsterdam(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)48 Ankara(COLUMN)cloudy(COLUMN)3 p.m.(COLUMN)54 Athens(COLUMN)cloudy(COLUMN)2 p.m.(COLUMN)63 Auckland(COLUMN)clear(COLUMN)midnight(COLUMN)64 Berlin(COLUMN)clear(COLUMN)1 p.m.(COLUMN)52 Birmingham(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)41 Brussels(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)48 Cairo(COLUMN)clear(COLUMN)2 p.m.(COLUMN)72 Casablanca(COLUMN)rain(COLUMN)noon(COLUMN)57 Copenhagen(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)45 Dublin(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)41 Geneva(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)48 Hong Kong(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)59 Lisbon(COLUMN)cloudy(COLUMN)noon(COLUMN)52 London(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)50 Madrid(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)48 Malta(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)70 Manila(COLUMN)clear(COLUMN)8 p.m.(COLUMN)79 Moscow(COLUMN)cloudy(COLUMN)3 p.m.(COLUMN)32 New Delhi(COLUMN)cloudy(COLUMN)5 p.m.(COLUMN)73 Nice(COLUMN)clear(COLUMN)1 p.m.(COLUMN)57 Oslo(COLUMN)clear(COLUMN)1 p.m.(COLUMN)28 Peking(COLUMN)clear(COLUMN)8 p.m.(COLUMN)48 Rome(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)64 Saigon(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)79 Sofia(COLUMN)clear(COLUMN)2 p.m.(COLUMN)68 Stockholm(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)25 Sydney(COLUMN)cloudy(COLUMN)10 p.m.(COLUMN)72 Tel Aviv(COLUMN)clear(COLUMN)2 p.m.(COLUMN)70 Tokyo(COLUMN)clear(COLUMN)9 p.m.(COLUMN)45 Tunis(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)61 Vienna(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)50 Warsaw(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)43(END TABLE) Temperatures (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)High(COLUMN)Low Acapulco(COLUMN)sunny(COLUMN)88(COLUMN)72 Barbados(COLUMN)sunny(COLUMN)84(COLUMN)75 Bermuda(COLUMN)pt. cldy(COLUMN)64(COLUMN)57 Calgary(COLUMN)cloudy(COLUMN)50(COLUMN)32 Culiacan(COLUMN)sunny(COLUMN)84(COLUMN)55 Edmonton(COLUMN)clear(COLUMN)41(COLUMN)25 Havana(COLUMN)pt. cldy.(COLUMN)75(COLUMN)64 Montego Bay(COLUMN)sunny(COLUMN)81(COLUMN)66 Mexico City(COLUMN)sunny(COLUMN)70(COLUMN)49 Monterrey(COLUMN)sunny(COLUMN)84(COLUMN)57 Montreal(COLUMN)clear(COLUMN)27(COLUMN)5 Nassau(COLUMN)cloudy(COLUMN)73(COLUMN)63 Ottawa(COLUMN)pt. cldy.(COLUMN)27(COLUMN)7 Regina(COLUMN)cloudy(COLUMN)28(COLUMN)25 St. Kitts(COLUMN)pt. cldy.(COLUMN)85(COLUMN)74 St. Thomas(COLUMN)pt. cldy.(COLUMN)86(COLUMN)74 Toronto(COLUMN)sleet(COLUMN)37(COLUMN)25 Vancouver(COLUMN)clear(COLUMN)48(COLUMN)36 Veracruz(COLUMN)sunny(COLUMN)81(COLUMN)63 Winnipeg(COLUMN)cloudy(COLUMN)35(COLUMN)18(END TABLE)