Washington: Today - increasing cloudiness with a chance of rain late in the day, high in the mid 60s, low near 45. The chance of rain is 30 percent through tonight. Winds will be from the southeast at 10 mph Friday - Gradual clearing and mild, high in the mid 70s.

Maryland and Virginia: increasing cloudiness with a chance of late afternoon or evening showers, high in the 60s, low in the 40s. Friday - Gradual clearing, highs will range from the 60s to mid 70s.

Lower Potomac and Chesapeake Bay - A chance of late afternoon or evening rain. Visibility will be less than 1 mile. Winds will shift from the northwest to the southeast at 10 to 20 knots. Waves will average 1 to 2 feet.

The National Weather Forecast for today - Showers, with snow over the high mountains, will extend from California across Montana and northern Utah. Scattered showers and thunderstorms will be seen from Wisconsin and Illinois through Tennessee and eastward over the Appalachians through Virginia, Pennsylvania and western New York. Mos of the rest of the nation will be sunny or partly cloudy. Seasonably cool temperatures will extend from California to the Rockies and across North Dakota, the northern Great Lakes region and also over most of the north and mid-Atlantic Coast states. Elsewhere mild readings will prevail.

Almanac Data for today: Sun rises 5:46 a.m., sets 6:36 p.m.; Moon rises 5:13 a.m., sets 5:49 p.m. Tides: high 7:12 a.m. and 7:39 p.m., low 1:20 a.m. and 1:49 p.m. High and low tides at the following locations may be obtained by subtracting the hours indicated from the hours above: Annapolis (3 1/4); Bloody Point Lighthouse (4 1/2); Deale, Md, (4 1/2); Colonial Beach (5 3/4); 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 33 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 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 near 5.0 feet today. Stages above 5 feet are considered hazardous for recreational purposes.

Washington data at 7 p.m. (EST) yesterday: Highest temperature since 7 a.m. yesterday, 69 degrees at 3:25 p.m. Lowest temperature since midnight, 53 degrees at 4:30 a.m. Excess of temperature since April 1, 34 degrees. Deficiency of temperature since Jan. 1, 229 degrees. Record high temperature for today, 92 degrees in 1929. Record low temperature for today, 26 degrees in 1898. Relative humidity: Maximum, 80 percent at 4 a.m. Minimum, 27 percent at 4 p.m. 24 hour precipitation, none. Deficiency of precipitation since April 1, 48 inches. Excess of precipitation since Jan. 1, 3.13 inches. Highest observed wind since 7 a.m. 26 miles per hour from the northwest at 9:53 a.m. Peak gust since 7 a.m., 37 miles per hour from the northwest at 9:38 a.m. Local Temp., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 midnte(COLUMN)57(COLUMN)75 1 a.m.(COLUMN)57(COLUMN)77 2 a.m.(COLUMN)56(COLUMN)77 3 a.m.(COLUMN)57(COLUMN)75 4 a.m.(COLUMN)55(COLUMN)80 5 a.m.(COLUMN)60(COLUMN)62 6 a.m.(COLUMN)64(COLUMN)54 7 a.m.(COLUMN)65(COLUMN)52 9 a.m.(COLUMN)66(COLUMN)50 8 a.m.(COLUMN)65(COLUMN)54 10 a.m.(COLUMN)66(COLUMN)47 11 a.m.(COLUMN)66(COLUMN)45 12 noon(COLUMN)67(COLUMN)36 1 p.m.(COLUMN)68(COLUMN)33 2 p.m.(COLUMN)67(COLUMN)33 3 p.m.(COLUMN)68(COLUMN)31 4 p.m.(COLUMN)68(COLUMN)27 5 p.m.(COLUMN)67(COLUMN)28 6 p.m.(COLUMN)64(COLUMN)30 7 p.m.(COLUMN)61(COLUMN)32(END TABLE) Temperatures ending 7 a.m. (EST) yesterday:(TABLE) City(COLUMN)H.(COLUMN)L. Albany(COLUMN)44(COLUMN)40 Albuquerque(COLUMN)76(COLUMN)39 Amarillo(COLUMN)83(COLUMN)62 Anchorage(COLUMN)45(COLUMN)29 Asheville(COLUMN)83(COLUMN)47 Atlanta(COLUMN)82(COLUMN)56 Atlantic City(COLUMN)47(COLUMN)46 Austin(COLUMN)85(COLUMN)67 Baltimore(COLUMN)63(COLUMN)54 Billings(COLUMN)63(COLUMN)39 Birmingham(COLUMN)82(COLUMN)57 Bismarck(COLUMN)57(COLUMN)41 Boise(COLUMN)54(COLUMN)37 Boston(COLUMN)43(COLUMN)40 Brownsville(COLUMN)86(COLUMN)70 Buffalo(COLUMN)71(COLUMN)37 Burlington, Vt.(COLUMN)44(COLUMN)38 Casper(COLUMN)62(COLUMN)35 Charleston, S.C.(COLUMN)79(COLUMN)64 Charleston, W.Va.(COLUMN)77(COLUMN)52 Charlotte(COLUMN)82(COLUMN)55 Cheyenne(COLUMN)62(COLUMN)34 Chicago(COLUMN)60(COLUMN)35 Cincinnati(COLUMN)70(COLUMN)42 Cleveland(COLUMN)72(COLUMN)37 Columbia, S.C.(COLUMN)85(COLUMN)54 Dal.-Ft. Worth(COLUMN)92(COLUMN)64 Dayton(COLUMN)71(COLUMN)40 Denver(COLUMN)68(COLUMN)41 Des Moines(COLUMN)61(COLUMN)42 Detroit(COLUMN)62(COLUMN)32 Duluth(COLUMN)46(COLUMN)24 Fairbanks(COLUMN)33(COLUMN)16 Great Falls(COLUMN)61(COLUMN)42 Helena(COLUMN)64(COLUMN)38 Jackson(COLUMN)83(COLUMN)61 Jacksonville(COLUMN)86(COLUMN)53 Juneau(COLUMN)48(COLUMN)27 Kansas City(COLUMN)66(COLUMN)51 Las Vegas(COLUMN)71(COLUMN)46 Little Rock(COLUMN)81(COLUMN)61 Los Angeles(COLUMN)62(COLUMN)48 Louisville(COLUMN)74(COLUMN)47 Memphis(COLUMN)83(COLUMN)61 Midland(COLUMN)90(COLUMN)63 Milwaukee(COLUMN)50(COLUMN)31 Mpls.-St. Paul(COLUMN)58(COLUMN)35 Nashville(COLUMN)80(COLUMN)54 New Orleans(COLUMN)80(COLUMN)61 New York(COLUMN)52(COLUMN)46 Norfolk(COLUMN)77(COLUMN)63 North Platte(COLUMN)68(COLUMN)47 Oklahoma City(COLUMN)85(COLUMN)66 Omaha(COLUMN)62(COLUMN)44 Orlando(COLUMN)87(COLUMN)58 Philadelphia(COLUMN)60(COLUMN)47 Phoenix(COLUMN)82(COLUMN)55 Pittsburgh(COLUMN)77(COLUMN)41 Portland, Me.(COLUMN)37(COLUMN)36 Portland, Or.(COLUMN)55(COLUMN)44 Raleigh(COLUMN)83(COLUMN)51 Rapid City(COLUMN)70(COLUMN)44 Reno(COLUMN)48(COLUMN)22 Richmond(COLUMN)83(COLUMN)59 St. Louis(COLUMN)70(COLUMN)45 St. Prbg-Tampa(COLUMN)85(COLUMN)63 Salt Lake City(COLUMN)64(COLUMN)41 San Antonio(COLUMN)83(COLUMN)67 San Diego(COLUMN)67(COLUMN)56 San Francisco(COLUMN)56(COLUMN)51 San Juan(COLUMN)83(COLUMN)73 St. Ste. Marie(COLUMN)35(COLUMN)33 Seattle(COLUMN)58(COLUMN)43 Shreveport(COLUMN)86(COLUMN)58 Sioux Falls(COLUMN)60(COLUMN)42 Spokane(COLUMN)47(COLUMN)35 Syracuse(COLUMN)60(COLUMN)35 Topeka(COLUMN)69(COLUMN)53 Tucson(COLUMN)81(COLUMN)49 Tulsa(COLUMN)79(COLUMN)63 Washington(COLUMN)70(COLUMN)53 Wichita(COLUMN)73(COLUMN)60(END TABLE) Temperatures Abroad Yesterday(TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)Temp. Aberdeen(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)45 Amsterdam(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)48 Ankara(COLUMN)rain(COLUMN) 3 p.m.(COLUMN)52 Athens(COLUMN)pt. cldy(COLUMN) 2 p.m.(COLUMN)66 Auckland(COLUMN)pt. cldy(COLUMN)midnight(COLUMN)57 Berlin(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)48 Birmingham(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)48 Brussels(COLUMN)pt. cldy(COLUMN) 1 p.m.(COLUMN)46 Casablanca(COLUMN)pt. cldy(COLUMN)noon(COLUMN)63 Copenhagen(COLUMN)pt. cldy(COLUMN) 1 p.m.(COLUMN)43 Dublin(COLUMN)pt. cldy(COLUMN) 1 p.m.(COLUMN)45 Geneva(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)52 Hong Kong(COLUMN)cloudy(COLUMN) 8 p.m.(COLUMN)72 Lisbon(COLUMN)cloudy(COLUMN)noon(COLUMN)54 London(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)52 Madrid(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)48 Malta(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)66 Manila(COLUMN)clear(COLUMN) 8 p.m.(COLUMN)84 Moscow(COLUMN)cloudy(COLUMN) 3 p.m.(COLUMN)37 New Delhi(COLUMN)clear(COLUMN) 5 p.m.(COLUMN)84 Nice(COLUMN)pt. cldy(COLUMN) 1 p.m.(COLUMN)61 Oslo(COLUMN)clear(COLUMN) 1 P.m.(COLUMN)45 Paris(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)48 Peking(COLUMN)clear(COLUMN) 8 p.m.(COLUMN)55 Rome(COLUMN)pt. cldy(COLUMN) 1 p.m.(COLUMN)61 Saigon(COLUMN)clear(COLUMN) 8 p.m.(COLUMN)84 Sofia(COLUMN)clear(COLUMN) 9 p.m.(COLUMN)46 Stockholm(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)37 Sydney(COLUMN)clear(COLUMN)10 p.m.(COLUMN)66 Tel Aviv(COLUMN)clear(COLUMN) 2 p.m.(COLUMN)72 Tokyo(COLUMN)clear(COLUMN) 9 p.m.(COLUMN)55 Tunis(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)64 Vienna(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)52 Warsaw(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)48(END TABLE) Temperatures (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)High(COLUMN)Low Acapulco(COLUMN)clear(COLUMN)87(COLUMN)70 Barbados(COLUMN)clear(COLUMN)84(COLUMN)72 Bogota(COLUMN)cloudy(COLUMN)63(COLUMN)54 Calgary(COLUMN)cloudy(COLUMN)55(COLUMN)25 Culiacan(COLUMN)clear(COLUMN)90(COLUMN)64 Edmonton(COLUMN)pt. cldy(COLUMN)54(COLUMN)30 Havana(COLUMN)fair(COLUMN)82(COLUMN)68 Kingston(COLUMN)pt. cldy(COLUMN)86(COLUMN)75 Montego Bay(COLUMN)pt. cldy(COLUMN)82(COLUMN)73 Mexico City(COLUMN)clear(COLUMN)82(COLUMN)50 Monterrey(COLUMN)clear(COLUMN)87(COLUMN)66 Montreal(COLUMN)cloudy(COLUMN)36(COLUMN)32 Ottawa(COLUMN)snow(COLUMN)34(COLUMN)32 Regina(COLUMN)pt. cldy(COLUMN)48(COLUMN)34 St. Kitts(COLUMN)cloudy(COLUMN)83(COLUMN)70 St. Thomas(COLUMN)pt. cldy(COLUMN)81(COLUMN)75 Toronto(COLUMN)cloudy(COLUMN)48(COLUMN)36 Vancouver(COLUMN)cloudy(COLUMN)57(COLUMN)41 Veracruz(COLUMN)clear(COLUMN)82(COLUMN)68 Winnipeg(COLUMN)clear(COLUMN)37(COLUMN)27(END TABLE)