Washington: Today - Partly cloudy, high in the mid 80s, now in the 60s. The chance of rain is 20 percent today and 10 percent tonight. Winds will be light and variable. Tuesday - Partly cloudy, high near 90.

Maryland and Virginia: Today - Partly cloudy with some chance of showers, high in the 80s, lows in the 60s. Tuesday - Partly cloudy, high in the 80s.

Extended Area Forecast for Wednesday through Friday - Partly cloudy, warm and humid through the period with a chance of a thundershowers each day. Highs will range from the 80s to low 90s, lows from the 60s to near 70.

Lower Potomac and Chesapeake Bay - Gradual clearing. Visibility will be 3 to 5 miles increasing to 5 miles or better by afternoon.Winds will be northwesterly at up to 12 knots. Waves will average 1 to 2 feet.

Atlantic Ocean Beaches from New Jersey to North Carolina: Cloudy with a good chance of showers, followed by clearing later in the day, high from the upper 70s to low 80s Tuesday - Partly cloudy, high in the 80s. Water temperatures will range from the 70s in the north to the mid 70s in the south.

West Virginia: Today and Tuesday - Sunny, highs will range from the mid 70s to mid 80s, lows will be in the 50s.

The National Weather Forecast for today - Scattered showers and thunderstorms will range across the northern Plains from the lower Mississippi Valley to Florida and southern Georgia, across the eastern Carolinas and over much of New England. There is a chance for isolated showers or thundershowers through the Rockies. Skies will be mostly sunny elsewhere. Mild temperatures are expected across the central and northern portions of the Rockies and the Plateau and over the southern half of New England. The remainder of the nation will continue warm to hot.

Almanac Data for today: The sun rises 5:56 a.m., sets 8:32 p.m.; moon rises 6:01 p.m., sets 3:23 a.m. Tides: high 5:55 a.m. and 6:26 p.m., low 1:05 a.m. High and low tides at the following locations may be obtained by subtracting the hours indicated from 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 1 p.m. period was 18 for the pollutant, photochemical oxidants. Index values between 0 and 25 indicate good air quality. When the index exceeds 100 the air is considered very unhealthy and individuals with lungs, heart and eye ailments are urged to restrict their activity. The forecast for today indicates that the air quality will worsen.

The National Weather Service forecasts the Potomac River stage at Little Falls should rise to near 4.0 feet today.

Washington data for yesterday: Highest temperature since midnight, 77 degrees at 4:30 a.m. Deficiency of temperature since July 1, 44 degrees. Deficiency of temperatures since Jan. 1, 194 degrees. Record high temperature for today, 99 degrees in 1887.Record low temperature for today, 56 degrees in 1929. Relative humidity: maximum, 97 percent at 8 a.m., minimum, 77 percent at 4 p.m. 24 hour precipitation, .02 since July 1 .86 inches. Excess of precipitation since Jan. 1, 3.39 inches.Highest observed wind since 8 a.m. 10 miles per hour from the south southwest at 12:53 p.m. Peak gust since 8 a.m., 16 miles per hour from the south at 9:11 a.m. Local Temps., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 Mid.(COLUMN)78(COLUMN)85 1 a.m.(COLUMN)77(COLUMN)91 2 a.m.(COLUMN)77(COLUMN)91 3 a.m.(COLUMN)77(COLUMN)91 4 a.m.(COLUMN)76(COLUMN)94 5 a.m.(COLUMN)76(COLUMN)94 6 a.m.(COLUMN)76(COLUMN)94 7 a.m.(COLUMN)77(COLUMN)91 8 a.m.(COLUMN)76(COLUMN)97 9 a.m.(COLUMN)76(COLUMN)97 10 a.m.(COLUMN)75(COLUMN)97 11 a.m.(COLUMN)75(COLUMN)88 12 noon(COLUMN)75(COLUMN)91 1 p.m.(COLUMN)76(COLUMN)88 2 p.m.(COLUMN)77(COLUMN)82 3 p.m.(COLUMN)76(COLUMN)85 4 p.m.(COLUMN)77(COLUMN)77 5 p.m. (COLUMN)77(COLUMN)77 6 p.m.(COLUMN)76(COLUMN)71 7 p.m.(COLUMN)75(COLUMN)71(END TABLE) Temperatures ending 8 a.m. ;EDT) yesterday:(TABLE) City(COLUMN)H.(COLUMN)L. Albany(COLUMN)82(COLUMN)63 Albuquerque(COLUMN)99(COLUMN)69 Amarillo(COLUMN)102(COLUMN)66 Anchorage(COLUMN)59(COLUMN)54 Asheville(COLUMN)73(COLUMN)65 Atlanta(COLUMN)82(COLUMN)68 Atlantic City(COLUMN)76(COLUMN)66 Austin(COLUMN)103(COLUMN)80 Baltimore(COLUMN)85(COLUMN)70 Billings(COLUMN)90(COLUMN)63 Birmingham(COLUMN)88(COLUMN)71 Bismarck(COLUMN)92(COLUMN)57 Boise(COLUMN)96(COLUMN)68 Boston(COLUMN)72(COLUMN)63 Brownsville(COLUMN)100(COLUMN)64 Buffalo(COLUMN)82(COLUMN)66 Burlington, Vt.(COLUMN)80(COLUMN)68 Casper(COLUMN)94(COLUMN)63 Charleston, S.C.(COLUMN)87(COLUMN)75 Charleston, W.V.(COLUMN)81(COLUMN)63 Charlotte(COLUMN)87(COLUMN)70 Cheyenne(COLUMN)93(COLUMN)55 Chicago(COLUMN)86(COLUMN)64 Cincinnati(COLUMN)78(COLUMN)61 Cleveland(COLUMN)89(COLUMN)68 Columbia, S.C.(COLUMN)86(COLUMN)70 Dal.-Ft. Worth(COLUMN)107(COLUMN)77 Dayton(COLUMN)84(COLUMN)62 Denver(COLUMN)95(COLUMN)60 Des Moines(COLUMN)90(COLUMN)60 Detroit(COLUMN)90(COLUMN)53 Duluth(COLUMN)77(COLUMN)56 El Paso(COLUMN)98(COLUMN)74 Fairbanks(COLUMN)71(COLUMN)53 Fargo(COLUMN)87(COLUMN)61 Flagstaff(COLUMN)87(COLUMN)52 Great Falls(COLUMN)95(COLUMN)58 Hartford(COLUMN)76(COLUMN)66 Helena(COLUMN)93(COLUMN)59 Honolulu(COLUMN)85(COLUMN)72 Houston(COLUMN)98(COLUMN)80 Indianapolis(COLUMN)81(COLUMN)66 Jackson(COLUMN)80(COLUMN)72 Jacksonville(COLUMN)90(COLUMN)74 Juneau(COLUMN)52(COLUMN)46 Kansas City(COLUMN)90(COLUMN)70 Las Vegas(COLUMN)113(COLUMN)86 Little Rock(COLUMN)90(COLUMN)71 Los Angeles(COLUMN)97(COLUMN)68 Louisville(COLUMN)74(COLUMN)63 Memphis(COLUMN)87(COLUMN)73 Miami Beach(COLUMN)86(COLUMN)80 Midland(COLUMN)99(COLUMN)73 Milwaukee(COLUMN)78(COLUMN)58 Mpls.-St. Paul(COLUMN)88(COLUMN)65 Nashville(COLUMN)83(COLUMN)66 New Orleans(COLUMN)91(COLUMN)73 New York(COLUMN)83(COLUMN)69 Norfolk(COLUMN)87(COLUMN)69 North Platte(COLUMN)96(COLUMN)66 Oklahoma City(COLUMN)100(COLUMN)74 Omaha(COLUMN)89(COLUMN)69 Orlando(COLUMN)93(COLUMN)74 Philadelphia(COLUMN)85(COLUMN)70 Phoenix(COLUMN)110(COLUMN)89 Pittsburgh(COLUMN)86(COLUMN)70 Portland, Me.(COLUMN)67(COLUMN)59 Portland, Ore.(COLUMN)74(COLUMN)59 Providence(COLUMN)72(COLUMN)62 Raleigh(COLUMN)85(COLUMN)70 Rapid City(COLUMN)96(COLUMN)70 Reno(COLUMN)92(COLUMN)43 Richmond(COLUMN)90(COLUMN)68 St. Louis(COLUMN)89(COLUMN)69 St. Prbg.-Tampa(COLUMN)88(COLUMN)78 Salt Lake City(COLUMN)96(COLUMN)76 San Antonio(COLUMN)100(COLUMN)77 San Diego(COLUMN)87(COLUMN)70 San Francisco(COLUMN)64(COLUMN)52 San Juan(COLUMN)90(COLUMN)79 St. Ste. Marie(COLUMN)61(COLUMN)44 Seattle(COLUMN)74(COLUMN)55 Shreveport(COLUMN)101(COLUMN)74 Sioux Falls(COLUMN)90(COLUMN)63 Spokane(COLUMN)91(COLUMN)59 Syracuse(COLUMN)89(COLUMN)61 Topeka(COLUMN)89(COLUMN)63 Tucson(COLUMN)104(COLUMN)76 Tulsa(COLUMN)98(COLUMN)70 Washington(COLUMN)89(COLUMN)75 Wichita(COLUMN)97(COLUMN)68(END TABLE) Temperatures Abroad Yesterday.

(TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)T. Aberdeen (COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)59 Amsterdam (COLUMN)cloudy (COLUMN)1 p.m. (COLUMN)61 Ankara (COLUMN)clear (COLUMN)3 p.m. (COLUMN)91 Athens (COLUMN)clear (COLUMN)2 p.m. (COLUMN)91 Auckland (COLUMN)clear (COLUMN)midnight (COLUMN)37 Berlin (COLUMN)cloudy (COLUMN)1 p.m. (COLUMN)57 Birmingham (COLUMN)cloudy (COLUMN)1 p.m. (COLUMN)61 Bonn (COLUMN)cloudy (COLUMN)1 p.m. (COLUMN)64 Brussels (COLUMN)cloudy (COLUMN)61 Cairo (COLUMN)clear (COLUMN)2 p.m. (COLUMN)95 Casablanca (COLUMN)clear (COLUMN)noon(COLUMN)77 Copenhagen (COLUMN)pt. cldy. (COLUMN)1 p.m. (COLUMN)57 Dublin (COLUMN)cloudy (COLUMN)1 p.m. (COLUMN)57 Geneva (COLUMN)clear (COLUMN)1 p.m. (COLUMN)73 Hong Kong (COLUMN)8 p.m. (COLUMN)86 Jerusalem (COLUMN)clear (COLUMN)2 p.m. (COLUMN)93 Lisbon (COLUMN)clear (COLUMN)noon (COLUMN)86 London (COLUMN)cloudy (COLUMN)1 p.m. (COLUMN)63 Madrid (COLUMN)clear (COLUMN)1 p.m. (COLUMN)99 Malta (COLUMN)clear (COLUMN)1 p.m. (COLUMN)86 Manila (COLUMN)pt. cldy. (COLUMN)8 p.m. (COLUMN)84 Moscow (COLUMN)cloudy (COLUMN)3 p.m. (COLUMN)72 New Delhi (COLUMN)pt. cloudy (COLUMN)5 p.m. (COLUMN)95 Nice (COLUMN)clear (COLUMN)1 p.m. (COLUMN)77 Oslo (COLUMN)pt. cldy. (COLUMN)1 p.m. (COLUMN)59 Paris (COLUMN)clear (COLUMN)1 p.m. (COLUMN)70 Peking (COLUMN)clear (COLUMN)8 p.m. (COLUMN)82 Rome (COLUMN)clear (COLUMN)1 p.m. (COLUMN)82 Saigon (COLUMN)pt. cldy. (COLUMN)8 p.m. (COLUMN)88 Sofia (COLUMN)pt. cldy. (COLUMN)2 p.m. (COLUMN)86 Stockholm (COLUMN)pt. cldy.(COLUMN)1 p.m. (COLUMN)57 Sydney (COLUMN)pt. cldy. (COLUMN)10 p.m. (COLUMN)54 Tokyo (COLUMN)clear(COLUMN)9 p.m. (COLUMN)79 Tunis (COLUMN)clear (COLUMN)1 p.m. (COLUMN)88 Vienna (COLUMN)pt. cldy. (COLUMN)1 p.m. (COLUMN)68 Warsaw (COLUMN)cloudy (COLUMN)10 p.m. (COLUMN)57(END TABLE)