Washington: Today - Partly sunny, high in upper 60s, low near 50. The chance of rain is 10 per cent through tonight. Sunday - Sunny, high in the mid 60s. Maryland and Virginia: Today - Partly cloudy, highs in the 60s, lows from the mid 40s to the 50s. Sunday - Sunny, highs in the 60s. Lower Potomac and Chesapeake Bay: Today - Partly cloudy. Visibility will be more than 5 miles. Winds will be from the northeast at near 10 knots today, shifting to from the east tonight. Waves in unprotected waters will be less than 2 feet.

The National Weather Forecast for Today - Rain is likely over portions of the northern half of California, most of Idaho - and over Oregon and Washington. Rain is also likely from northeastern Arkansas through the Atlantic Coast from South Carolina to Virginia. Temperatures will be mild over the plains and southern Rockies and from southern Louisiana through Florida and Georgia to southern South Carolina. Most of the remainder of the country will be cool.

Almanac Data for Today - Sun rises 7:32 a.m., sets 6:12 p.m.; moon rises 4:12 p.m. sets 9:29 a.m. Tides: high in 10:72 a.m. and 10:30 p.m. low 4:57 a.m. and 5:03 p.m. High and low tides at the following locations can be obtained by subtracting the hours indicated from the tides above. Annapolis (1 1/2); Bloody Point Lighthouse (4 1/2); Deale, Md. (4 1/2); Colonial Beach (6); Norfolk (1 1/2); Virginia Beach (1); Solomons Island (6 1/2); Point Lookout (7).

Extended Area Forecast for Monday through Wednesday: Fair through the period. Highs will be from the upper 60s to the low 70s, low from the upper 40s to the mid 50s. Normal Washington temperatures for the period are a high of 64 and a low of 44.

West Virginia: Today - Partly cloudy, highs in the 60s, lows from the 40s to the low 50s. Sunday - Partly cloudy, highs in the 60s.

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 26 for the pollutant, photochemical oxidants. Index values between 25 and 49 indicate fair air quality. When the index exceeds 100 the air is considered very unhealthy and indivduals with lung, heart and eye ailments are urged to restrict their activity. The forecast for today indicates that the air quality will improve.

The National Weather Service forecast the Potomac River stage at Little Falls should be near 4 feet today. Local Temp., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 midn't(COLUMN)68(COLUMN)84 1 a.m.(COLUMN)66(COLUMN)84 2 a.m.(COLUMN)67(COLUMN)84 3 a.m.(COLUMN)64(COLUMN)87 4 a.m.(COLUMN)63(COLUMN)87 5 a.m.(COLUMN)65(COLUMN)87 6 a.m.(COLUMN)66(COLUMN)84 7 a.m.(COLUMN)66(COLUMN)84 8 a.m.(COLUMN)65(COLUMN)87 9 a.m.(COLUMN)68(COLUMN)81 10 a.m.(COLUMN)69(COLUMN)76 11 a.m.(COLUMN)12 noon(COLUMN)72 64 1 p.m.(COLUMN)73(COLUMN)60 2 p.m.(COLUMN)74(COLUMN)56 3 p.m.(COLUMN)73(COLUMN)66 4 p.m.(COLUMN)71(COLUMN)49 5 p.m.(COLUMN)70(COLUMN)51 6 p.m.(COLUMN)69(COLUMN)53 7 p.m.(COLUMN)67(COLUMN)54(END TABLE) Temperatures ending 8 a.m. (EDT) Yesterday(TABLE) City(COLUMN)H.(COLUMN)L. Albany(COLUMN)72(COLUMN)46 Albuquerque(COLUMN)75(COLUMN)41 Amarillo(COLUMN)72(COLUMN)46 Anchorage(COLUMN)47(COLUMN)34 Asheville(COLUMN)69(COLUMN)55 Atlanta(COLUMN)76(COLUMN)55 Atlantic City(COLUMN)64(COLUMN)60 Austin(COLUMN)81(COLUMN)66 Baltimore(COLUMN)67(COLUMN)62 Billings(COLUMN)62(COLUMN)38 Birmingham(COLUMN)67(COLUMN)54 Bismarck(COLUMN)62(COLUMN)36 Boise(COLUMN)58(COLUMN)40 Boston(COLUMN)72(COLUMN)56 Brownsville(COLUMN)84(COLUMN)74 Buffalo(COLUMN)66(COLUMN)45 Burlington(COLUMN)67(COLUMN)42 Casper(COLUMN)66(COLUMN)35 Charleston, S.C.(COLUMN)73(COLUMN)57 Ch'leston, W.Va.(COLUMN)64(COLUMN)56 Charlotte(COLUMN)68(COLUMN)62 Cheyenne(COLUMN)57(COLUMN)34 Chicago(COLUMN)64(COLUMN)50 Cincinnati(COLUMN)65(COLUMN)45 Cleveland(COLUMN)62(COLUMN)52 Columbia, S.C.(COLUMN)72(COLUMN)55 Columbus(COLUMN)63(COLUMN)46 Dal.-Ft. Worth(COLUMN)82(COLUMN)62 Dayton(COLUMN)67(COLUMN)42 Denver(COLUMN)63(COLUMN)34 Des Moines(COLUMN)61(COLUMN)54 Detroit(COLUMN)64(COLUMN)42 Duluth(COLUMN)62(COLUMN)29 El Paso(COLUMN)81(COLUMN)48 Fairbanks(COLUMN)35(COLUMN)23 Fargo(COLUMN)64(COLUMN)33 Flagstaff(COLUMN)64(COLUMN)37 Great Falls(COLUMN)63(COLUMN)38 Hartford(COLUMN)78(COLUMN)55 Helena(COLUMN)56(COLUMN)31 Honolulu(COLUMN)87(COLUMN)72 Houston(COLUMN)85(COLUMN)71 Indianapolis(COLUMN)70(COLUMN)45 Jackson, Miss.(COLUMN)78(COLUMN)49 Jacksonville(COLUMN)77(COLUMN)59 Juneau(COLUMN)47(COLUMN)43 Kansas City(COLUMN)80(COLUMN)57 Las Vegas(COLUMN)82(COLUMN)54 Little Rock(COLUMN)83(COLUMN)61 Los Angeles(COLUMN)72(COLUMN)60 Louisville(COLUMN)66(COLUMN)50 Memphis(COLUMN)77(COLUMN)54 Miami Beach(COLUMN)84(COLUMN)69 Midland-Odessa(COLUMN)70(COLUMN)55 Milwaukee(COLUMN)62(COLUMN)44 Mpls.-St. Paul(COLUMN)67(COLUMN)36 Nashville(COLUMN)64(COLUMN)48 New Orleans(COLUMN)75(COLUMN)59 New York(COLUMN)70(COLUMN)60 Norfolk(COLUMN)68(COLUMN)63 North Platte(COLUMN)68(COLUMN)42 Omaha(COLUMN)62(COLUMN)52 Orlando(COLUMN)82(COLUMN)58 Philadelphia(COLUMN)69(COLUMN)58 Phoenix(COLUMN)88(COLUMN)66 Pittsburgh(COLUMN)71(COLUMN)52 Portland, Maine(COLUMN)67(COLUMN)41 Portland, Ore.(COLUMN)54(COLUMN)45 Providence(COLUMN)75(COLUMN)59 Raleigh(COLUMN)67(COLUMN)61 Rapid City(COLUMN)61(COLUMN)42 Reno(COLUMN)58(COLUMN)31 Richmond(COLUMN)74(COLUMN)64 St. Louis(COLUMN)82(COLUMN)51 St. Prbg.-Tampa(COLUMN)81(COLUMN)58 Salt Lake City(COLUMN)76(COLUMN)50 San Antonio(COLUMN)77(COLUMN)65 San Diego(COLUMN)72(COLUMN)63 San Francisco(COLUMN)63(COLUMN)56 San Juan(COLUMN)88(COLUMN)78 St. Ste. Marie(COLUMN)51(COLUMN)35 Seattle(COLUMN)55(COLUMN)46 Shreveport(COLUMN)85(COLUMN)42 Sioux Falls(COLUMN)69(COLUMN)37 Spokane(COLUMN)47(COLUMN)33 Syracuse(COLUMN)70(COLUMN)48 Topeka(COLUMN)83(COLUMN)57 Tucson(COLUMN)83(COLUMN)59 Tulsa(COLUMN)87(COLUMN)62 Washington(COLUMN)69(COLUMN)63 Wichita(COLUMN)84(COLUMN)64(END TABLE) Temperatures Abroad Yesterday(TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)Temp. Aberdeen(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)57 Amsterdam(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)57 Ankara(COLUMN)pt. cldy(COLUMN)3 p.m.(COLUMN)59 Athens(COLUMN)clear(COLUMN)2 p.m.(COLUMN)70 Auckland(COLUMN)cloudy(COLUMN)midnight(COLUMN)57 Berlin(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)52 Birmingham(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)54 Brussels(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)50 Casablanca(COLUMN)clear(COLUMN)noon(COLUMN)70 Copenhagen(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)52 Dublin(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)57 Geneva(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)55 Hong Kong(COLUMN)pt. cldy(COLUMN)8 p.m.(COLUMN)77 Lisbon(COLUMN)clear(COLUMN)noon(COLUMN)64 London(COLUMN)clear(COLUMN)1 p.m.(COLUMN)55 Madrid(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)63 Malta(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)75 Manila(COLUMN)rain(COLUMN)8 p.m.(COLUMN)79 Moscow(COLUMN)cloudy(COLUMN)3 p.m.(COLUMN)37 New Delhi(COLUMN)clear(COLUMN)5 p.m.(COLUMN)86 Nice(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)68 Oslo(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)54 Paris(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)54 Peking(COLUMN)rain(COLUMN)8 p.m.(COLUMN)48 Rome(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)72 Saigon(COLUMN)pt. cldy(COLUMN)8 p.m.(COLUMN)84 Sofla(COLUMN)clear(COLUMN)2 p.m.(COLUMN)64 Stockholm(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)52 Sydney(COLUMN)clear(COLUMN)10 p.m.(COLUMN)75 Tel Aviv(COLUMN)pt. cldy(COLUMN)2 p.m.(COLUMN)77 Tokyo(COLUMN)haze(COLUMN)9 p.m.(COLUMN)64 Tunis(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)73 Vienna(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)54 Warsaw(COLUMN)clear(COLUMN)1 p.m.(COLUMN)54(END TABLE) Temperatures (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)High(COLUMN)Low Acapulco(COLUMN)clear(COLUMN)91(COLUMN)77 Barbados(COLUMN)cloudy(COLUMN)81(COLUMN)79 Bermuda(COLUMN)pt. cldy(COLUMN)81(COLUMN)74 Boyota(COLUMN)pt. cldy(COLUMN)80(COLUMN)60 Calgery(COLUMN)cloudy(COLUMN)54(COLUMN)30 Edmonton(COLUMN)cloudy(COLUMN)51(COLUMN)25 Havana(COLUMN)clear(COLUMN)85(COLUMN)73 Kingston(COLUMN)clear(COLUMN)27(COLUMN)77 Manto Bay(COLUMN)rain(COLUMN)87(COLUMN)72 Mexico City(COLUMN)haze(COLUMN)75(COLUMN)55 Monterrey(COLUMN)pt. cldy(COLUMN)72(COLUMN)64 Montreal(COLUMN)clear(COLUMN)61(COLUMN)45 Nassau(COLUMN)pt. cldy(COLUMN)86(COLUMN)72 Ottawa(COLUMN)pt. cldy(COLUMN)64(COLUMN)43 Regina(COLUMN)clear(COLUMN)59(COLUMN)36 St. Kitts(COLUMN)cloudy(COLUMN)87(COLUMN)36 St. Thomas(COLUMN)clear(COLUMN)90(COLUMN)77 Toronto(COLUMN)clear(COLUMN)64(COLUMN)37 Vancouver(COLUMN)rain(COLUMN)59(COLUMN)50 Veracruz(COLUMN)pt. cldy(COLUMN)86(COLUMN)72 Winnipeg(COLUMN)clear(COLUMN)63(COLUMN)32(END TABLE)