Washington: Today - Partly cloudy, chance of thundershowers, high near 90, low near 70s. The chance of rain is 30 per cent today and 10 per cent tonight. Thursday - Sunny, high near 90.

Maryland and Virginia: Today - Partly cloudy, chance of thunderstorms, highs from the low 80s to the low 90s, lows in the 60s. Thursday - Sunny, highs from the low 80s to the low 90s.

Atlantic Ocean Beaches from Cape May to Cape Hatteras: Today - Partly cloudy, chance of thundershowers, highs in the 80s. Thursday - Sunny, high in the 80s. Water temperatures will range from the mid 60s in the north to near 80 in the south.

Lower Potomac and Chesapeake Bay: Today - Chance of thundershowers. Visibility will be from 2 1/2 to 5 miles. Wind will be from the southwest at less than 20 knots. Waves in unprotected waters will average less than 2 feet.

Extended Area Forecast for Friday through Sunday - Fair through the period, with a chance of thundershowers on each day. Highs will be in the upper 80s, lows from the mid to the upper 60s. Normal Washington temperatures for the period are a high of 87 and a low of 68.

West Virginia: Today - Partly cloudy, highs from the mid 70s to the mid 80s, lows from the low 50s to the low 60s. Thursday - Sunny, highs from the upper 70s to the mid 80s.

The National Weather Forecast for today - showers and thundershowers are likely from Michigan through the lower Great Lakes and the upper Ohio Valley and across New England and the central Appalachians to the mid Atlantic coast. There will be a chance of widely scattered showers and thundershowers from the lower Mississippi Valley and the eastern Gulf Coast through the lower Ohio Valley. Most of the rest of the nation will have sunny skies. There will be little change in temperatures, with hot weather persisting over northern New England, Georgia, South Carolina and the plains of North Carolina, as well as in California over the deserts and interior valleys. The rest of the country will be seasonably warm or mild.

Almanac Data for Today - Sun rises 5:45 a.m., sets 8:37 p.m.; moon rises 7:05 p.m., sets 4:21 a.m. Tides: High 6:58 a.m. and 7:29 p.m., low 1:10 a.m. and 1:59 p.m. High and low tides at the following locations can be obtained by subtracting the hours indicated from the tides above. Annapolis (3 1/2); Bloody Port Lighthouse (4 1/2); Deale, Md. (4 1/2); Colonial Beach (6); Norfolk (1 1/2); Virginia Beach (1); Solomors 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 65 for the pollutant, photochemical oxidants. Index values between 50 and 99 indicate unhealthy 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 2.8 feet. Local Temp., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 mid.(COLUMN)78(COLUMN)62 1 a.m.(COLUMN)78(COLUMN)62 2 a.m.(COLUMN)77(COLUMN)64 3 a.m.(COLUMN)76(COLUMN)67 4 a.m.(COLUMN)76(COLUMN)67 5 a.m.(COLUMN)76(COLUMN)67 6 a.m.(COLUMN)76(COLUMN)67 7 a.m.(COLUMN)76(COLUMN)67 8 a.m.(COLUMN)77(COLUMN)64 9 a.m.(COLUMN)80(COLUMN)61 10 a.m.(COLUMN)81(COLUMN)69 11 a.m.(COLUMN)85(COLUMN)58 12 noon(COLUMN)88(COLUMN)55 1 p.m.(COLUMN)88(COLUMN)55 2 p.m.(COLUMN)91(COLUMN)52 3 p.m.(COLUMN)90(COLUMN)56 4 p.m.(COLUMN)89(COLUMN)32 5 p.m.(COLUMN)94(COLUMN)49 6 p.m.(COLUMN)93(COLUMN)49 7 p.m.(COLUMN)90(COLUMN)54(END TABLE) Temperatures ending 8 a.m. (EDT) Yesterday(TABLE) City(COLUMN)H.(COLUMN)L. Albany(COLUMN)$86(COLUMN) Albuquerque(COLUMN)97(COLUMN)65 Amarillo(COLUMN)96(COLUMN)71 Anchorage(COLUMN)65(COLUMN)56 Asheville(COLUMN)87(COLUMN)61 Atlanta(COLUMN)91(COLUMN)72 Atlantic City(COLUMN)78(COLUMN)68 Austin(COLUMN)82(COLUMN)75 Baltimore(COLUMN)89(COLUMN)70 Billings(COLUMN)88(COLUMN)54 Birmingham(COLUMN) 85(COLUMN)76 Bismarck(COLUMN)87(COLUMN)52 Boise(COLUMN)84(COLUMN)51 Boston(COLUMN)75(COLUMN)67 Brownsville(COLUMN) 90(COLUMN)78 Buffalo(COLUMN)85(COLUMN)68 Burlington(COLUMN)87(COLUMN)62 Casper(COLUMN)91(COLUMN)55 Charleston, SC(COLUMN)97(COLUMN)80 Charleston, W.V.(COLUMN)85(COLUMN)70 Charlotte(COLUMN)92(COLUMN)74 Chevenne(COLUMN)86(COLUMN)54 Chicago(COLUMN)92(COLUMN)74 Cincinnati(COLUMN)82(COLUMN)69 Cleveland(COLUMN)88(COLUMN)88 69 Columbia, SC(COLUMN)96(COLUMN)71 Columbus(COLUMN)88(COLUMN)63 Dal.Ft. Worth(COLUMN)99(COLUMN)72 Dayton(COLUMN)87(COLUMN)70 Denver(COLUMN)94(COLUMN)63 Des Moines(COLUMN)96(COLUMN)72 Detroit(COLUMN)87(COLUMN)66 Duluth(COLUMN)79(COLUMN)67 El Paso(COLUMN)104(COLUMN)70 Fairbanks(COLUMN)69(COLUMN)51 Faigo(COLUMN)83(COLUMN)57 Flagstaff(COLUMN)87(COLUMN)53 Great Falls(COLUMN)83(COLUMN)49 Hartford(COLUMN)87(COLUMN)65 Helena(COLUMN)79(COLUMN)46 Honolulu(COLUMN)85(COLUMN)74 Houston(COLUMN)80(COLUMN)78 Indianapolis(COLUMN)82(COLUMN)71 Jackson, Miss.(COLUMN)95(COLUMN)75 Jacksonville(COLUMN)97(COLUMN)74 Juneau(COLUMN)59(COLUMN)68 Kansas City(COLUMN)89(COLUMN)69 Las Vegas(COLUMN)114(COLUMN)84 Little Rock(COLUMN)37(COLUMN)72 os Angeles(COLUMN)79(COLUMN)60 Louisville(COLUMN)86(COLUMN)72 Memphis(COLUMN)90(COLUMN)78 Miami Beach(COLUMN)88(COLUMN)81 Midland-Odessa(COLUMN)101(COLUMN)73 Milwaukee(COLUMN)86(COLUMN)69 Mpls.-St. Paul(COLUMN)90(COLUMN)66 Nashville(COLUMN)90(COLUMN)73 New Orleans(COLUMN)93(COLUMN)79 New York(COLUMN)83(COLUMN)70 Norfolk(COLUMN)88(COLUMN)73 North Platte(COLUMN)93(COLUMN)62 Oklahoma City(COLUMN)92(COLUMN)75 Omaha(COLUMN)96(COLUMN)66 Orlando(COLUMN)94(COLUMN)74 Philadelphia(COLUMN)84(COLUMN)64 Phoenix(COLUMN)110(COLUMN)83 Pittsburgh(COLUMN)84(COLUMN)65 Portland, Maine(COLUMN)75(COLUMN)67 Portland, Ore(COLUMN)76(COLUMN)56 Providence(COLUMN)79(COLUMN)64 Raleigh(COLUMN)93(COLUMN)68 Rapid City(COLUMN)87(COLUMN)58 Reno(COLUMN)96(COLUMN)56 Richmond(COLUMN)95(COLUMN)70 St. Louis(COLUMN)87(COLUMN)74 St. Prbg. Tampa(COLUMN)94(COLUMN)73 Salt Lake City(COLUMN)92(COLUMN)60 San Antonio(COLUMN)91(COLUMN)76(KEY OFF)San Diego 72(COLUMN)62 San Francisco(COLUMN)60(COLUMN)54 San Juan(COLUMN)88(COLUMN)78 St. Ste Marie(COLUMN)67(COLUMN)58 Seatle(COLUMN)72(COLUMN)53 Shreveport(COLUMN)92(COLUMN)69 Sioux Falls(COLUMN)92(COLUMN)60 Spokane(COLUMN)80(COLUMN)54 Syracuse(COLUMN)85(COLUMN)60 Topeka(COLUMN)90(COLUMN)77 Tucson(COLUMN)103(COLUMN)74 Washington(COLUMN)90(COLUMN)76 Wichita(COLUMN)94(COLUMN)75(END TABLE) Temperatures Abroad Yesterday(TABLE) City(COLUMN)weather(COLUMN)Time(COLUMN)Tem. Aberdeen(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)54 Amsterdam(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)63 Angara(COLUMN)rain(COLUMN)3 p.m.(COLUMN)68 Atherns(COLUMN)pt. cldy(COLUMN)8 p.m.(COLUMN)82 Berlin(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)68 Birmingham(COLUMN)rain(COLUMN)1 P.m.(COLUMN)59 Brussells(COLUMN)Pt. cldy(COLUMN)1 p.m.(COLUMN)66 Cairo(COLUMN)clear(COLUMN)2 p.m.(COLUMN)91 Casablanca(COLUMN)cloudy(COLUMN)noon(COLUMN)72 Copenhagen(COLUMN)clear(COLUMN)1 p.m.(COLUMN)66 Dublin(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)61 Geneva(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)68 Hong Kong(COLUMN)pt. cldy(COLUMN)8 p.m.(COLUMN)84 Lisbon(COLUMN)pt. cldy(COLUMN)noon(COLUMN)73 London(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)61 Madrid(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)86 Malta(COLUMN)clear(COLUMN)1 P.m.(COLUMN)77 Moscow(COLUMN)rain(COLUMN)3 p.m.(COLUMN)68 New Delhi(COLUMN)coldy(COLUMN)5 p.m.(COLUMN)82 Nice(COLUMN)clear(COLUMN)1 p.m.(COLUMN)73 Oslo(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)61 Paris(COLUMN)cloudy(COLUMN)1 P.m.(COLUMN)70 Peking(COLUMN)cloudy(COLUMN)3 p.m.(COLUMN)77 Roem(COLUMN)clear(COLUMN)1 p.m.(COLUMN)79 Saigon(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)81 Sofia(COLUMN)pt. cldy(COLUMN)2 p.m.(COLUMN)64 Stockholm(COLUMN)Pt. cldy(COLUMN)1 p.m.(COLUMN)63 Tel Aviv(COLUMN)clear(COLUMN)2 p.m.(COLUMN)88 Tokyo(COLUMN)cloudy(COLUMN)9 p.m.(COLUMN)75 Tunis(COLUMN)clear(COLUMN)1 p.m.(COLUMN)84 Vienna(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)70 Warsaw(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)68(END TABLE) Temperatures (Western Hemisphere)(TABLE) $ City(COLUMN)weather(COLUMN)High(COLUMN)Low Acapulco(COLUMN)pt. cldy(COLUMN)95(COLUMN)81 Bermuda(COLUMN)Pt cldy(COLUMN)79(COLUMN)73 Calgary(COLUMN)cloudy(COLUMN)66(COLUMN)46 Culiacan(COLUMN)pt. cldy(COLUMN)97(COLUMN)78 Edmonton(COLUMN)pt. cldy(COLUMN)72(COLUMN)43 Havana(COLUMN)sunny(COLUMN)90(COLUMN)72 Kingston(COLUMN)fair(COLUMN)90(COLUMN)73 Montego Bay(COLUMN)sunny(COLUMN)90(COLUMN)72 Mexico City(COLUMN)pt. cldy(COLUMN)77(COLUMN)61 Monterrey(COLUMN)fair(COLUMN)99(COLUMN)71 Montreal(COLUMN)clear(COLUMN)82(COLUMN)61 Nassau(COLUMN)fair(COLUMN)90(COLUMN)71 Ottawa(COLUMN)clear(COLUMN)86(COLUMN)61 Regina(COLUMN)clear(COLUMN)66(COLUMN)45 St. Kitts(COLUMN)pt. cldy(COLUMN)88(COLUMN)78 Toronto(COLUMN)haze(COLUMN)84(COLUMN)59 Vancouver(COLUMN)cloudy(COLUMN)68(COLUMN)55 Veracruz(COLUMN)pt cldy(COLUMN)89(COLUMN)77 Winnipeg(COLUMN)clear(COLUMN)75(COLUMN)55(END TABLE)(KEYWORD)