Washington: Today - Cloudy, high in mid to upper 60s, low in low 50s. Chance of rain 40 per cent today, 70 per cent tonight. Sunday - Rain, high in 60s.

Maryland: Today - Chance of rain, highs in 60s, low near 50. Chance of rain today with rain likely tonight. Sunday - rain, high in 60s.

Virginia: Today - Rain, high in 60s, low in low 50s. Sunday - Rain, high in 60s.

Lower Potomac and Chesapeake Bay: Today - Chance of rain today with rain likely tonight, visibility of 5 miles or more decreasing to 2 miles or less at times through tonight. Winds should be southeasterly at 12 to 22 knots today becoming southerly at 10 to 18 knots tonight.

Extended Area Outlook: For Monday through Wednesday - Chance of rain Monday followed by partial clearing Tuesday or Wednesday. Highs should average in mid 50s to mid 60s, lows in 40s. Washington's normal temperature range for this time of years is from 54 to 35.

West Virginia: Today - Rain, high in 60s to low 70s, low in mid 40s to mid 50s. Sunday - Rain, highs in upper 50s to upper 60s.

The National Weather Forecast for Today - Rain or rainshowers will fall from eastern Nebraska and eastern Kansas across the Mississippi Valley and other areas eastward except for southern New England and Florida. Scattered thundershowers will accompany the rain from the middle and lower Mississippi Valley into the southeastern U.S. Rain will also fall across the Pacific northwest and northern California. Elsewhere fair or partly cloudy skies are forecast. It will be cooler across the eastern portions of the Plains but little temperature change is expected elsewhere.

The Council of Governments' Air Quality Index for yesterday showed the high reading in the Washington area during the 2 to 3 p.m. period was 36 for the pollutant, photochemical oxidants. Index values between 25 and 49 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 remain about the same.

The National Weather Service forecasts that the Potomac River stage at Little Falls will decrease to 4.0 feet by Monday morning.

Washington data at 7 p.m. (EST) yesterday: Highest temperature since 7 a.m. yesterday, 73 degrees at 3:03 p.m. Lowest temperature since midnight, 45 degrees at 5:15 a.m. Excess of temperature since March 1, 99 degrees. Deficiency of temperature since Jan. 1, 158 degrees. Record high temperature for today, 75 degrees in 1923. Record low temperature for today, 11 degrees in 1900. Relative humidity: Maximum, 89 per cent at 7 a.m.; Minimum 46 per cent at 4 p.m. 24 hour precipitation, none. Deficiency of precipitation since March 1, 1.12 inches. Deficiency of precipitation since Jan. 1, 4.03 inches. Highest observed wind since 7 a.m. 13 miles per hour from the south at 12 p.m. Peak gust since 7 a.m., 15 miles per hour from the south at 1:42 p.m. Local Temp., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 midn.(COLUMN)50(COLUMN)80 1 a.m.(COLUMN)50(COLUMN)74 2 a.m.(COLUMN)48(COLUMN)80 3 a.m.(COLUMN)50(COLUMN)77 4 a.m.(COLUMN)48(COLUMN)89 5 a.m.(COLUMN)46(COLUMN)86 6 a.m.(COLUMN)46(COLUMN)89 7 a.m.(COLUMN)47(COLUMN)89 8 a.m.(COLUMN)49(COLUMN)86 9 a.m.(COLUMN)56(COLUMN)13 10 a.m.(COLUMN)60(COLUMN)45 11 a.m.(COLUMN)64(COLUMN)60 12 noon(COLUMN)69(COLUMN)57 1 p.m.(COLUMN)72(COLUMN)48 2 p.m.(COLUMN)72(COLUMN)51 3 p.m.(COLUMN)70(COLUMN)51 4 p.m.(COLUMN)72(COLUMN)46 5 p.m.(COLUMN)68(COLUMN)20(END TABLE) Temperatures ending 7 a.m. (EST) yesterday:(TABLE) City(COLUMN)H.(COLUMN)L. Albany(COLUMN)72(COLUMN)90 Albuquerque(COLUMN)49(COLUMN)29 Amarillo(COLUMN)70(COLUMN)39 Anchorage(COLUMN)28(COLUMN)24 Atlanta(COLUMN)61(COLUMN)53 Atlantic City(COLUMN)50(COLUMN)44 Austin(COLUMN)75(COLUMN)58 Baltimore(COLUMN)69(COLUMN)38 Billings(COLUMN)44(COLUMN)25 Bismarck(COLUMN)49(COLUMN)34 Boise(COLUMN)46(COLUMN)22 Boston(COLUMN)70(COLUMN)42 Brownsville(COLUMN)78(COLUMN)68 Buffalo(COLUMN)60(COLUMN)38 Burlington, Vt.(COLUMN)57(COLUMN)32 Casper(COLUMN)34(COLUMN)28 Charleston, S.C.(COLUMN)65(COLUMN)59 Ch'l't'n, W.Va.(COLUMN)67(COLUMN)39 Charlotte, N.C.(COLUMN)66(COLUMN)54 Cheyenne(COLUMN)38(COLUMN)22 Chicago(COLUMN)66(COLUMN)52 Cincinnati(COLUMN)68(COLUMN)39 Cleveland(COLUMN)67(COLUMN)35 Columbia, S.C.(COLUMN)70(COLUMN)58 Columbus, Ohio(COLUMN)65(COLUMN)39 Dal-Ft. Worth(COLUMN)69(COLUMN)53 Dayton(COLUMN)69(COLUMN)43 Denver(COLUMN)44(COLUMN)27 Des Moines(COLUMN)68(COLUMN)53 Duluth(COLUMN)50(COLUMN)37 El Paso(COLUMN)67(COLUMN)37 Fairbanks(COLUMN)5(COLUMN)3 Fargo(COLUMN)53(COLUMN)40 Flagstaff(COLUMN)37(COLUMN)18 Great Falls(COLUMN)50(COLUMN)20 Hartford(COLUMN)70(COLUMN)33 Helena(COLUMN)43(COLUMN)21 Honolulu(COLUMN)83(COLUMN)73 Houston(COLUMN)72(COLUMN)67 Indianapolis(COLUMN)67(COLUMN)44 Jackson, Miss.(COLUMN)65(COLUMN)60 Jacksonville(COLUMN)70(COLUMN)57 Juneau(COLUMN)39(COLUMN)38 Kansas City(COLUMN)69(COLUMN)56 Las Vegas(COLUMN)57(COLUMN)43 Little Rock(COLUMN)69(COLUMN)56 Los Angeles(COLUMN)70(COLUMN)51 Louisville(COLUMN)71(COLUMN)46 Miami Beach(COLUMN)78(COLUMN)73 Midland(COLUMN)85(COLUMN)38 Milwaukee(COLUMN)59(COLUMN)41 Mpls.-St. Paul(COLUMN)56(COLUMN)45 Nashville(COLUMN)71(COLUMN)53 New Orleans(COLUMN)79(COLUMN)67 New York(COLUMN)69(COLUMN)50 Norfolk(COLUMN)68(COLUMN)51 North Platte(COLUMN)54(COLUMN)33 Oklahoma City(COLUMN)69(COLUMN)53 Omaha(COLUMN)66(COLUMN)56 Orlando(COLUMN)73(COLUMN)65 Philadelphia(COLUMN)68(COLUMN)42 Phoenix(COLUMN)69(COLUMN)50 Pittsburgh(COLUMN)66(COLUMN)31 Portland, Me.(COLUMN)58(COLUMN)32 Portland, Ore.(COLUMN)51(COLUMN)38 Providence(COLUMN)69(COLUMN)35 Raleigh(COLUMN)68(COLUMN)47 Rapid City(COLUMN)40(COLUMN)34 Reno(COLUMN)42(COLUMN)22 Richmond(COLUMN)70(COLUMN)46 St. Louis(COLUMN)87(COLUMN)57 St. Prbg.-Tampa(COLUMN)70(COLUMN)68 Salt Lake City(COLUMN)40(COLUMN)27 San Lake City(COLUMN)40(COLUMN)27 San Antonio(COLUMN)79(COLUMN)60 San Diego(COLUMN)67(COLUMN)49 San Francisco(COLUMN)58(COLUMN)51 San Juan, P.R.(COLUMN)67(COLUMN)73 St. Ste. Marie(COLUMN)50(COLUMN)25 Seattle(COLUMN)54(COLUMN)41 Shreveport(COLUMN)78(COLUMN)67 Sioux Falls(COLUMN)50(COLUMN)42 Spokane(COLUMN)47(COLUMN)30 Syracuse(COLUMN)67(COLUMN)32 Tucson(COLUMN)61(COLUMN)40 Tulsa(COLUMN)67(COLUMN)58 Washington(COLUMN)68(COLUMN)45 Wichita(COLUMN)69(COLUMN)52(END TABLE) Temperatures Abroad Yesterday(TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)Temp. Aberdeen(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)46 Amsterdam(COLUMN)rain(COLUMN)1 p.m.(COLUMN)58 Ankara(COLUMN)cloudy(COLUMN)3 p.m.(COLUMN)39 Athens(COLUMN)cloudy(COLUMN)2 p.m.(COLUMN)55 Auckland(COLUMN)clear(COLUMN)m'night(COLUMN)64 Berlin(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)57 Birmingham(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)50 Brussels(COLUMN)rain(COLUMN)1 p.m.(COLUMN)46 Cairo(COLUMN)clear(COLUMN)2 p.m.(COLUMN)68 Casablanca(COLUMN)pt. cldy.(COLUMN)noon(COLUMN)70 Copenhagen(COLUMN)clear(COLUMN)1 p.m.(COLUMN)46 Dublin(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)45 Geneva(COLUMN)rain(COLUMN)1 p.m.(COLUMN)46 Hong Kong(COLUMN)clear(COLUMN)3 p.m.(COLUMN)70 Libson(COLUMN)rain(COLUMN)noon(COLUMN)48 London(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)52 Madrid(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)52 Malta(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)64 Manila(COLUMN)clear(COLUMN)8 p.m.(COLUMN)79 Moscow(COLUMN)cloudy(COLUMN)3 p.m.(COLUMN)36 New Delhi(COLUMN)clear(COLUMN)5 p.m.(COLUMN)88 Nice(COLUMN)rain(COLUMN)1 p.m.(COLUMN)55 Olso(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)34 Paris(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)54 Peking(COLUMN)clear(COLUMN)8 p.m.(COLUMN)46 Rome(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)59 Saigon(COLUMN)clear(COLUMN)8 p.m.(COLUMN)81 Sofia(COLUMN)clear(COLUMN)2 p.m.(COLUMN)50 Stockholm(COLUMN)clear(COLUMN)1 p.m.(COLUMN)43 Sydney(COLUMN)clear(COLUMN)10 p.m.(COLUMN)73 Tel Aviv(COLUMN)clear(COLUMN)2 p.m.(COLUMN)64 Tokyo(COLUMN)cloudy(COLUMN)9 p.m.(COLUMN)48 Tunis(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)70 Vienna(COLUMN)clear(COLUMN)1 p.m.(COLUMN)55 Warsaw(COLUMN)clear(COLUMN)1 p.m.(COLUMN)55(END TABLE) Temperatures (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)High(COLUMN)Low Acapulco(COLUMN)pt. cldy.(COLUMN)87(COLUMN)73 Barbados(COLUMN)pt. cldy.(COLUMN)82(COLUMN)75 Bermuda(COLUMN)rain(COLUMN)66(COLUMN)65 Bogota(COLUMN)cloudy(COLUMN)70(COLUMN)46 Calgary(COLUMN)clear(COLUMN)46(COLUMN)27 Culiacan(COLUMN)pt. cldy.(COLUMN)90(COLUMN)57 Edmonton(COLUMN)clear(COLUMN)39(COLUMN)21 Havana(COLUMN)cloudy(COLUMN)84 69 Kingston(COLUMN)sunny(COLUMN)68(COLUMN)77 Montego Bay(COLUMN)sunny(COLUMN)64(COLUMN)69 Mexico City(COLUMN)fair(COLUMN)32(COLUMN)55 Monterrey(COLUMN)cloudy(COLUMN)82(COLUMN)57 Montreal(COLUMN)clear(COLUMN)50(COLUMN)30 Nassau(COLUMN)pt. cldy.(COLUMN)81(COLUMN)66 Ottawa(COLUMN)clear(COLUMN)55(COLUMN)30 Regina(COLUMN)cloudy(COLUMN)50(COLUMN)27 St. Kitts(COLUMN)pt. cldy.(COLUMN)85(COLUMN)74 St. Thomas(COLUMN)sunny(COLUMN)86(COLUMN)75 Toronto(COLUMN)pt. cldy.(COLUMN)61(COLUMN)32 Veracruz(COLUMN)sunny(COLUMN)84(COLUMN)60 Winnipeg(COLUMN)rain(COLUMN)41(COLUMN)34(END TABLE)