Washington: Today - Partly cloudy, warm and humid with a chance of a late afternoon or evening thundershowers, high near 90, low in the 70s. The chance of rain is 30 percent through tonight. Winds will be from the southwest at 10 to 15 mph. Friday - Variable cloudiness with a chance of showers, high near 90.

Maryland and Virginia: Today - Partly cloudy, warm and humid, highs from the 80s to mid 90s, lows from the 60s to mid 70s. Friday - Variable cloudiness with a chance of showers or thundershowers, highs in the 80s to low 90s.

Extended Area Forecast for Saturday through Monday - Variable cloudiness, warm and humid with a chance of mainly afternoon or evening thundershowers through the period. Highs will average from the 80s to low 90s, lows from the mid 60s to low 70s. Normal Washington temperatures are a high of 88 and a low of 69.

Lower Potomac and Chesapeake Bay - Fair with a chance of a late thunderstorms. Visibility will be 3 to 5 miles diminishing to less than 1 mile late tonight. Winds will be from the southwest increasing to 15 knots. Waves will average 1 to 2 feet.

Atlantic Ocean Beaches from New Jersey to North Carolina: Today - Mostly sunny, quite warm and humid, high in the 80s. Friday - Partly cloudy, hot and humid with a chance of showers or thunderstorms, highs in the 80s to near 90. Water temperatures will range from near 70 from Maryland northward to near 80 in North Carolina.

West Virginia: Today and Friday - Partly cloudy with a chance of late afternoon or evening thundershowers, high in the 80s, low in the 60s.

The national weather forecast for today - Showers and occasional thunderstorms will extend from the Gulf Coast across the lower Mississippi Valley, the Atlantic Coast, the Tennessee Valley, the Ohio Valley, the lower Great Lakes and New England. Showers and thundershowers will also be scattered from the southern Rockies into the southern Plateau and across southeastern portions of the Great Basin, as well as from the upper Missouri Valley across the Pacific Northwest. Temperatures will be hot over northern New England. Oklahoma, the upper two thirds of the Missouri Valley and into the northern Rockies. Elsewhere temperatures across the nation will continue to be warm.

Almanac Data for today: The sun rises 6:04 a.m., sets 8:24 p.m.; moon sets 2:79 p.m. Tides: high 2:42 a.m. and 3:03 p.m., low 9:33 a.m. and 9:46 p.m. High and low tides at the following locations may be obtained by subtracting the hours above: Annapolis (3 1/4), Bloody Point Lighthouse (4 1/2), Deale, Md. (4 1/2), Colonial Beach (5 1/4), Norfolk (1), Virginia Beach (3/4), Solomons Island (6 1/4), Point Lookout (7).

The Council of Governments' Air Quality Index for yesterday showed the high reading in the Washington area during the 3 p.m. period was 30 for the pollutant, photochemical oxidants. Index values between 25 and 49 indicate fair air quality. When the indes exceeds 100 the air is considered very unhealthy and individuals with lung, heart and eye ailments are urged to restrict their activity. The forecast for today indicates that the air quality will deteriorate.

The National Weather Service forecasts the Potomac River Stage at Little Falls should remain near 3.1 feet today. Local Temps., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 midnite(COLUMN)74(COLUMN)85 1 a.m.(COLUMN)74(COLUMN)85 2 a.m.(COLUMN)72(COLUMN)88 3 a.m.(COLUMN)72(COLUMN)90 4 a.m.(COLUMN)72(COLUMN)90 5 a.m.(COLUMN)73(COLUMN)87 6 a.m.(COLUMN)73(COLUMN)87 7 a.m.(COLUMN)73(COLUMN)87 8 a.m.(COLUMN)74(COLUMN)85 9 a.m.(COLUMN)75(COLUMN)87 10 a.m.(COLUMN)77(COLUMN)85 11 a.m.(COLUMN)78(COLUMN)82 12 noon(COLUMN)80(COLUMN)79 1 p.m.(COLUMN)83(COLUMN)72 2 p.m.(COLUMN)84(COLUMN)72 3 p.m.(COLUMN)85(COLUMN)70 4 p.m.(COLUMN)86(COLUMN)68 5 p.m.(COLUMN)87(COLUMN)64 6 p.m.(COLUMN)86(COLUMN)66 7 p.m.(COLUMN)85(COLUMN)68(END TABLE) Temperatures ending 8 a.m. (EDT) yesterday:(TABLE) City(COLUMN)H.(COLUMN)L Albany(COLUMN)82(COLUMN)60 Albuquerque(COLUMN)93(COLUMN)70 Amarillo(COLUMN)94(COLUMN)69 Anchorage(COLUMN)68(COLUMN)56 Asheville(COLUMN)83(COLUMN)60 Atlanta(COLUMN)91(COLUMN)66 Atlantic City(COLUMN)75(COLUMN)65 Austin(COLUMN)96(COLUMN)76 Baltimore(COLUMN)75(COLUMN)71 Billings(COLUMN)89(COLUMN)59 Birmingham(COLUMN)92(COLUMN)71 Bismarck(COLUMN)90(COLUMN)56 Boise(COLUMN)100(COLUMN)68 Boston(COLUMN)78(COLUMN)57 Brownsville(COLUMN)97(COLUMN)77 Buffalo(COLUMN)86(COLUMN)70 Burlington, Vt.(COLUMN)84(COLUMN)67 Casper(COLUMN)91(COLUMN)54 Charleston, S.C.(COLUMN)96(COLUMN)74 Charleston, W. Va.(COLUMN)80(COLUMN)67 Charlotte(COLUMN)90(COLUMN)69 Cheyenne(COLUMN)92(COLUMN)54 Chicago(COLUMN)83(COLUMN)73 Cincinnati(COLUMN)84(COLUMN)66 Cleveland(COLUMN)85(COLUMN)71 Columbia, S.C.(COLUMN)95(COLUMN)49 Columbus(COLUMN)80(COLUMN)70 Dal.-Ft. Worth(COLUMN)98(COLUMN)79 Dayton(COLUMN)82(COLUMN)68 Denver(COLUMN)98(COLUMN)60 Des Moines(COLUMN)95(COLUMN)75 Detroit(COLUMN)87(COLUMN)68 Duluth(COLUMN)88(COLUMN)65 El Paso(COLUMN)96(COLUMN)73 Evansville(COLUMN)86(COLUMN)68 Fairbanks(COLUMN)71(COLUMN)54 Fargo(COLUMN)94(COLUMN)57 Flagstaff(COLUMN)82(COLUMN)55 Great Falls(COLUMN)91(COLUMN)53 Hartford(COLUMN)82(COLUMN)50 Helena(COLUMN)92(COLUMN)55 Honolulu(COLUMN)90(COLUMN)75 Houston(COLUMN)94(COLUMN)78 Indianapolis(COLUMN)87(COLUMN)70 Jackson(COLUMN)92(COLUMN)77 Jacksonville(COLUMN)93(COLUMN)73 Juneau(COLUMN)54(COLUMN)47 Kansas City(COLUMN)97(COLUMN)78 Las Vegas(COLUMN)103(COLUMN)82 Little Rock(COLUMN)93(COLUMN)74 Los Angeles(COLUMN)85(COLUMN)65 Louisville(COLUMN)87(COLUMN)67 Memphis(COLUMN)92(COLUMN)74 Miami Beach(COLUMN)86(COLUMN)80 Midland(COLUMN)91(COLUMN)70 Milwaukee(COLUMN)83(COLUMN)72 Mpls.-St. Paul(COLUMN)90(COLUMN)71 Nashville(COLUMN)86(COLUMN)70 New Orleans(COLUMN)91(COLUMN)77 New York(COLUMN)81(COLUMN)64 Norfolk(COLUMN)85(COLUMN)70 North Platte(COLUMN)100(COLUMN)56 Oklahoma City(COLUMN)101(COLUMN)75 Omaha(COLUMN)92(COLUMN)66 Orlando(COLUMN)92(COLUMN)71 Philadelphia(COLUMN)81(COLUMN)69 Phoenix(COLUMN)101(COLUMN)83 Pittsburgh(COLUMN)84(COLUMN)71 Portland, Ma.(COLUMN)79(COLUMN)55 Portland, Ore.(COLUMN)96(COLUMN)68 Providence(COLUMN)78(COLUMN)55 Raleigh(COLUMN)91(COLUMN)68 Rapid City(COLUMN)90(COLUMN)62 Reno(COLUMN)101(COLUMN)64 Richmond(COLUMN)87(COLUMN)69 St. Louis(COLUMN)90(COLUMN)72 St. Prbg.-Tampa(COLUMN)91(COLUMN)73 Salt Lake City(COLUMN)100(COLUMN)65 San Antonio(COLUMN)95(COLUMN)75 San Diego(COLUMN)79(COLUMN)70 San Francisco(COLUMN)64(COLUMN)56 San Juan(COLUMN)89(COLUMN)77 St. Ste. Marie(COLUMN)78(COLUMN)63 Seattle(COLUMN)88(COLUMN)64 Shreveport(COLUMN)96(COLUMN)76 Sioux Falls(COLUMN)92(COLUMN)66 Spokane(COLUMN)93(COLUMN)64 Syracuse(COLUMN)84(COLUMN)64 Topeka(COLUMN)93(COLUMN)75 Tucson(COLUMN)95(COLUMN)75 Tulsa(COLUMN)102(COLUMN)82 Washington(COLUMN)82(COLUMN)72 Wichita(COLUMN)102(COLUMN)77(END TABLE) Temperatures Abroad Yesterday(TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)Temp. Aberdeen(COLUMN)drizzle(COLUMN)1 p.m.(COLUMN)55 Amsterdam(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)70 Ankara(COLUMN)clear(COLUMN)3 p.m.(COLUMN)77 Athens(COLUMN)clear(COLUMN)2 p.m.(COLUMN)84 Auckland(COLUMN)clear(COLUMN)midnight(COLUMN)48 Berlin(COLUMN)clear(COLUMN)1 p.m.(COLUMN)82 Birmingham(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)64 Bonn(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)79 Brussels(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)72 Cairo(COLUMN)clear(COLUMN)2 p.m.(COLUMN)88 Casablanca(COLUMN)clear(COLUMN)noon(COLUMN)77 Copenhagen(COLUMN)clear(COLUMN)1 p.m.(COLUMN)68 Dublin(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)64 Geneva(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)75 Hong Kong(COLUMN)rain(COLUMN)8 p.m.(COLUMN)77 Jerusalem(COLUMN)clear(COLUMN)2 p.m.(COLUMN)75 Lisbon(COLUMN)clear(COLUMN)noon(COLUMN)77 London(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)68 Madrid(COLUMN)clear(COLUMN)1 p.m.(COLUMN)93 Malta(COLUMN)clear(COLUMN)1 p.m.(COLUMN)81 Manila(COLUMN)rain(COLUMN)8 p.m.(COLUMN)77 Moscow(COLUMN)cloudy(COLUMN)3 p.m.(COLUMN)57 New Delhi(COLUMN)pt. cldy.(COLUMN)5 p.m.(COLUMN)91 Nice(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)77 Oslo(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)64 Paris(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)63 Peking(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)81 Rome(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)82 Saigon(COLUMN)rain(COLUMN)8 p.m.(COLUMN)77 Sofia(COLUMN)clear(COLUMN)2 p.m.(COLUMN)75 Stockholm(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)68 Sydney(COLUMN)clear(COLUMN)10 p.m.(COLUMN)55 Tokyo(COLUMN)clear(COLUMN)9 p.m.(COLUMN)81 Tunis(COLUMN)clear(COLUMN)1 p.m.(COLUMN)86 Vienna(COLUMN)clear(COLUMN)1 p.m.(COLUMN)79 Warsaw(COLUMN)pt. cldy.(COLUMN)10 p.m.(COLUMN)75(END TABLE) Temperatures (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)H(COLUMN)L Acapulco(COLUMN)pt. cldy.(COLUMN)90(COLUMN)77 Barbados(COLUMN)pt. cldy.(COLUMN)88(COLUMN)77 Bermuda(COLUMN)cloudy(COLUMN)89(COLUMN)76 Calgary(COLUMN)clear(COLUMN)81(COLUMN)50 Edmonton(COLUMN)clear(COLUMN)79(COLUMN)48 Havana(COLUMN)pt. cldy.(COLUMN)90(COLUMN)73 Kingston(COLUMN)fair(COLUMN)92(COLUMN)73 Montego Bay(COLUMN)sunny(COLUMN)90(COLUMN)73 Mexico City(COLUMN)haze(COLUMN)73(COLUMN)55 Monterrey(COLUMN)clear(COLUMN)92(COLUMN)71 Montreal(COLUMN)cloudy(COLUMN)82(COLUMN)68 Nassau(COLUMN)pt. cldy.(COLUMN)90(COLUMN)73 Regina(COLUMN)clear(COLUMN)84(COLUMN)46 St. Kitts(COLUMN)fair(COLUMN)88(COLUMN)77 St. Thomas(COLUMN)fair(COLUMN)91(COLUMN)78 Toronto(COLUMN)cloudy(COLUMN)82(COLUMN)66 Vancouver(COLUMN)pt. cldy.(COLUMN)77(COLUMN)57 Veracruz(COLUMN)cloudy(COLUMN)85(COLUMN)73 Winnipeg(COLUMN)clear(COLUMN)86(COLUMN)57(END TABLE)