Washington: Today - Partly cloudy, high 83 to 86, low 68 to 74. Chance of showers is 60 percent; 50 percent tonight. Winds will be southerly at 15 knots. Sunday - Partly cloudy, high near 90.

Maryland and Virginia: Today - Partly cloudy. With a chance of thunderstorms, high in mid 80s, low near 70. Sunday - Partly cloudy, high near 90.

Lower Potomac and Chesapeake Bay: Today - Fair, visibility more than five miles except in rain. Winds will be southerly at 15 knots. Waves in unprotected waters will be 2 feet.

Atlantic Ocean Beaches from New Jersey to North Carolina: Today - Cloudy with a chance of thundershowers, high in 80s. Sunday - Partly cloudy with a chance of showers, high in 80s. Water temperatures will be in low 70s to the north and low 80s in the south.

Extended Area Outlook for Monday through Wednesday: There will be isolated showers or thunderstorms early in the period otherwise partly cloudy and humid. Highs will average in 80s to the low 90s and lows from the mid 60s to the mid 70s. Normal Washington temperatures for the period will be a high of 87 and a low 68.

The National Weather Forecast for today - Showers and thundershowers will extend from central New England through Florida, across the lower Great Lakes, the Ohio Valley, the Tennessee Valley and the eastern Gulf states. Showers will also reach from the Washington and Oregon coast over the northern Rockies into Upper Missouri valley. Temperatures will be hot from Oklahoma through the central and northern Plains, and very hot across much of Kansas. Mild temperatures will be general over the northern half of the Pacific Coast into the upper intermountain region, as well as from the New England coast through North Carolina. Temperatures elsewhere over the nation will be seasonably warm.

Almanac Data for today: The sun rises 6:19 a.m., sets 8:07 p.m.; moon rises 2:41 a.m., sets. Tides: high 2:27 a.m. and 2:48 p.m., low 8:33 a.m. and 9:28 p.m. High and low tides at the following locations may be obtained by subtracting the hours indicated from the hours above: Annapolis (3 1/2), Bloody Point Lighthouse (4 1/2), Deale, Md. (4 1/2), Colonial Beach (5 1/4), Norfolk (1), Virginia Beach (5 1/4), 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 2 to 3 p.m. period was 72 for the pollutant, photochemical oxidants. Index values between 50 and 99 indicate unhealthy air quality. When the index 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 improve.

The National Weather Service forecasts the Potomac River Stage at Little Falls should fall to 4.3 feet today. Local Temps., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 midnite(COLUMN)78(COLUMN)79 1 a.m.(COLUMN)78(COLUMN)82 2 a.m.(COLUMN)78(COLUMN)88 3 a.m.(COLUMN)75(COLUMN)91 4 a.m.(COLUMN)75(COLUMN)91 5 a.m.(COLUMN)75(COLUMN)91 6 a.m.(COLUMN)74(COLUMN)91 7 a.m.(COLUMN)73(COLUMN)97 8 a.m.(COLUMN)76(COLUMN)88 9 a.m.(COLUMN)78(COLUMN)82 10 a.m.(COLUMN)80(COLUMN)77 11 a.m.(COLUMN)82(COLUMN)72 12 noon(COLUMN)85(COLUMN)66 1 p.m.(COLUMN)87(COLUMN)61 2 p.m.(COLUMN)88(COLUMN)59 3 p.m.(COLUMN)89(COLUMN)58 4 p.m.(COLUMN)89(COLUMN)60 5 p.m.(COLUMN)89(COLUMN)60 6 p.m.(COLUMN)88(COLUMN)61 7 p.m.(COLUMN)85(COLUMN)70(END TABLE) Temperatures ending 8 a.m. (EDT) yesterday:(TABLE) City (COLUMN)H.(COLUMN)L. Albany(COLUMN)61(COLUMN)54 Albuquerque(COLUMN)89(COLUMN)62 Amarillo(COLUMN)89(COLUMN)66 Anchorage(COLUMN)72(COLUMN)60 Asheville(COLUMN)78(COLUMN)64 Atlanta(COLUMN)82(COLUMN)69 Atlantic City(COLUMN)80(COLUMN)69 Austin(COLUMN)95(COLUMN)74 Baltimore(COLUMN)84(COLUMN)70 Billings(COLUMN)95(COLUMN)61 Birmingham(COLUMN)83(COLUMN)71 Bismarck(COLUMN)94(COLUMN)61 Boise(COLUMN)94(COLUMN)54 Boston(COLUMN)85(COLUMN)64 Brownsville(COLUMN)96(COLUMN)78 Buffalo(COLUMN)78(COLUMN)58 Burlington(COLUMN)78(COLUMN)52 Casper(COLUMN)90(COLUMN)57 Charleston, S.C.(COLUMN)86(COLUMN)76 Charleston, W.Va.(COLUMN)83(COLUMN)64 Charlotte(COLUMN)84(COLUMN)70 Cheyenne(COLUMN)82(COLUMN)56 Chicago(COLUMN)78(COLUMN)68 Cincinnati(COLUMN)79(COLUMN)66 Cleveland(COLUMN)76(COLUMN)58 Columbia, S.C.(COLUMN)85(COLUMN)72 Columbus(COLUMN)81(COLUMN)61 Dal.-Ft. Worth(COLUMN)97(COLUMN)72 Dayton(COLUMN)81(COLUMN)61 Denver(COLUMN)89(COLUMN)55 Des Moines(COLUMN)82(COLUMN)65 Detroit(COLUMN)77(COLUMN)59 Duluth(COLUMN)76(COLUMN)60 El Paso(COLUMN)92(COLUMN)68 Fairbanks(COLUMN)76(COLUMN)57 Fargo(COLUMN)88(COLUMN)64 Flagstaff(COLUMN)82(COLUMN)59 Great Falls(COLUMN)95(COLUMN)63 Hartford(COLUMN)81(COLUMN)55 Helena(COLUMN)94(COLUMN)54 Honolulu(COLUMN)87(COLUMN)73 Houston(COLUMN)94(COLUMN)79 Indianapolis(COLUMN)87(COLUMN)70 Jackson, Miss.(COLUMN)89(COLUMN)73 Jacksonville(COLUMN)91(COLUMN)70 Juneau(COLUMN)62(COLUMN)50 Kansas City(COLUMN)85(COLUMN)65 Las Vegas(COLUMN)109(COLUMN)83 Little Rock(COLUMN)90(COLUMN)70 Los Angeles(COLUMN)86(COLUMN)68 Louisville(COLUMN)89(COLUMN)68 Memphis(COLUMN)87(COLUMN)74 Miami Beach(COLUMN)85(COLUMN)80 Midland-Odessa(COLUMN)91(COLUMN)64 Milwaukee(COLUMN)73(COLUMN)63 Mpls.-St. Paul(COLUMN)81(COLUMN)61 Nashville(COLUMN)90(COLUMN)72 New Orleans(COLUMN)83(COLUMN)77 New York(COLUMN)83(COLUMN)71 Norfolk(COLUMN)87(COLUMN)71 North Platte(COLUMN)87(COLUMN)58 Oklahoma City(COLUMN)94(COLUMN)68 Omaha(COLUMN)83(COLUMN)65 Orlando(COLUMN)92(COLUMN)74 Philadelphia(COLUMN)83(COLUMN)73 Phoenix(COLUMN)107(COLUMN)80 Pittsburgh(COLUMN)77(COLUMN)61 Portland, Me.(COLUMN)85(COLUMN)51 Portland, Ore.(COLUMN)83(COLUMN)61 Providence(COLUMN)35(COLUMN)39 Raleigh(COLUMN)86(COLUMN)70 Rapid City(COLUMN)91(COLUMN)58 Reno(COLUMN)96(COLUMN)47 Richmond(COLUMN)89(COLUMN)70 St. Louis(COLUMN)92(COLUMN)65 St. Prbg.-Tampa(COLUMN)91(COLUMN)76 Salt Lake City(COLUMN)99(COLUMN)71 San Antonio(COLUMN)92(COLUMN)75 San Diego(COLUMN)80(COLUMN)72 San Francisco(COLUMN)59(COLUMN)55 San Juan(COLUMN)89(COLUMN)81 St. Ste. Marie(COLUMN)76(COLUMN)52 Seattle(COLUMN)75(COLUMN)58 Shreveport(COLUMN)96(COLUMN)72 Sioux Falls(COLUMN)82(COLUMN)65 Spokane(COLUMN)88(COLUMN)60 Syracuse(COLUMN)80(COLUMN)55 Topeka(COLUMN)86(COLUMN)64 Tucson(COLUMN)99(COLUMN)75 Tulsa(COLUMN)93(COLUMN)72 Washington(COLUMN)89(COLUMN)73 Wichita(COLUMN)92(COLUMN)68(END TABLE) Temperatures Abroad Yesterday(TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)Temp. Aberdeen(COLUMN)clear(COLUMN)1 p.m.(COLUMN)61 Amsterdam(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)61 Ankara(COLUMN)clear(COLUMN)3 p.m.(COLUMN)84 Athens(COLUMN)clear(COLUMN)2 p.m.(COLUMN)86 Berlin(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)61 Birmingham(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)66 Bonn(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)61 Brussels(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)63 Casablanca(COLUMN)clear(COLUMN)12 p.m.(COLUMN)75 Copenhagen(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)68 Dublin(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)64 Geneva(COLUMN)clear(COLUMN)1 p.m.(COLUMN)66 Hong Kong(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)81 Jerusalem(COLUMN)clear(COLUMN)2 p.m.(COLUMN)86 Lisbon(COLUMN)clear(COLUMN)12 p.m.(COLUMN)81 London(COLUMN)clear(COLUMN)1 p.m.(COLUMN)86 Madrid(COLUMN)clear(COLUMN)1 p.m.(COLUMN)82 Malta(COLUMN)clear(COLUMN)1 p.m.(COLUMN)81 Manila(COLUMN)rain(COLUMN)8 p.m.(COLUMN)75 Moscow(COLUMN)cloudy(COLUMN)3 p.m.(COLUMN)57 New Delhi(COLUMN)cloudy(COLUMN)5 p.m.(COLUMN)81 Nice(COLUMN)clear(COLUMN)1 p.m.(COLUMN)73 Oslo(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)66 Paris(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)66 Peking(COLUMN)clear(COLUMN)8 p.m.(COLUMN)77 Rome(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)77 Saigon(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)81 Sofia(COLUMN)pt. cldy(COLUMN)2 p.m.(COLUMN)70 Stockholm(COLUMN)clear(COLUMN)1 p.m.(COLUMN)68 Sydney(COLUMN)clear(COLUMN)10 p.m.(COLUMN)50 Toyko(COLUMN)cloudy(COLUMN)9 p.m.(COLUMN)86 Tunis(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)82 Vienna(COLUMN)storm(COLUMN)1 p.m.(COLUMN)60 Warsaw(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)68(END TABLE) Temperature (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)High(COLUMN)Low Acapulco(COLUMN)sunny(COLUMN)90(COLUMN)77 Barbados(COLUMN)cloudy(COLUMN)84(COLUMN)77 Bermuda(COLUMN)fair(COLUMN)87(COLUMN)79 Calgary(COLUMN)pt. cldy(COLUMN)86(COLUMN)50 Edmonton(COLUMN)cloudy(COLUMN)90(COLUMN)54 Havana(COLUMN)pt. cldy(COLUMN)90(COLUMN)73 Kingston(COLUMN)pt. cldy(COLUMN)91(COLUMN)81 Montego Bay(COLUMN)pt. cldy(COLUMN)90(COLUMN)75 Mexico City(COLUMN)pt. cldy(COLUMN)75(COLUMN)59 Monterrey(COLUMN)fair(COLUMN)95(COLUMN)73 Montreal(COLUMN)clear(COLUMN)75(COLUMN)55 Ottawa(COLUMN)clear(COLUMN)75(COLUMN)55 Regina(COLUMN)clear(COLUMN)95(COLUMN)57 St. Kitts(COLUMN)fair(COLUMN)89(COLUMN)76 St. Thomas(COLUMN)fair(COLUMN)88(COLUMN)80 Toronto(COLUMN)cloudy(COLUMN)73(COLUMN)52 Vancouver(COLUMN)cloudy(COLUMN)68(COLUMN)59 Veracruz(COLUMN)cloudy(COLUMN)86(COLUMN)75 Winnipeg(COLUMN)clear(COLUMN)84(COLUMN)63(END TABLE)