Washington: Today - Variable cloudiness, high in the mid 60s, low near 40. The chance of rain is 10 percent today, 20 percent tonight. Winds will be northwesterly at 10 to 15 mph. Sunday - Variable cloudiness, high in the mid 60s.

Maryland: Today - Variable cloudiness and cool, high near 60, low in the 30s. Sunday - Variable cloudiness, high again near 60.

Virginia: Today - Variable cloudiness with a chance of rain in the southwest late tonight or Sunday, high in the 60s, low near 40. Sunday - Variable cloudiness, high in the 60s.

Lower Potomac and Chesapeake Bay - Fair with winds coming from the northwest at up 15 knots. Visibility will be 5 miles or more. Waves will average near 2 feet.

Extended Area Forecast for Monday through Wednesday - Mostly cloudy through the period with a chance of rain Tuesday or Wednesday. Highs will average from the mid 50s to the low 70s, lows from the upper 30s to the 40s. Normal Washington area temperatures for the period are a high of 68 and a low of 46.

West Virginia: Today - Partly cloudy with a chance of showers, high in the 60s, low near 40. Sunday - Variable cloudiness, high in the 60s.

The National Weather Forecast for Today - Showers are likely along the central Pacific Coast. There is a good chance for Rain, with snow at the higher elevations, extending Inland to the western portions of the central and northern Rockies. Scattered showers will fall in northern Maine, the northern Great Lakes, the Ohio Valley, the Tennessee Valley, the middle Mississippi Valley and along the middle and upper Missouri Valley. Mild temperatures will extend from New Mexico eastward across Texas and the Gulf Coast states into South Carolina. Cool temperatures will prevail elsewhere.

Almanac Data for today: Sun rises 5:32 a.m., sets 6:45 p.m.; Moon rises 11:32 a.m., sets 1:00 a.m. Tides: high 1:13 a.m. and 1:29 p.m., low 8:12 a.m. and 8:47 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 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 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 be near 4.2 feet today.

Washington data at 7 p.m. (EST) yesterday: Highest temperature since 7 a.m. yesterday, 69 degrees at 1:45 p.m. Lowest temperature since midnight 47 degrees at 5:45 a.m. Excess of temperature since April, 92 degrees. Deficiency of temperature since Jan. 1, 171 degrees. Record high temperature for today, 89 degrees in 1941. Record low temperature for today, 28 degrees in 1904. Relative humidity: Maximum, 43 percent at 4 a.m. Minimum, 17 percent at 4 p.m. 24 hour precipitation, none. Deficiency of precipitation since April 1, 1.09 inches. Excess of precipitation since Jan. 1, 2.51 inches. Highest observed wind since 7 a.m. 25 miles per hour from the northwest at 4 p.m. Peak gust since 7 a.m., 46 miles per hour from the northwest at 1:38 p.m. Local Temp., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 midnight(COLUMN)60(COLUMN)28 1 a.m.(COLUMN)57(COLUMN)33 2 a.m.(COLUMN)54(COLUMN)37 3 a.m.(COLUMN)52(COLUMN)41 4 a.m.(COLUMN)50(COLUMN)43 5 a.m.(COLUMN)49(COLUMN)36 6 a.m.(COLUMN)47(COLUMN)39 7 a.m.(COLUMN)49(COLUMN)37 8 a.m.(COLUMN)50(COLUMN)38 9 a.m.(COLUMN)53(COLUMN)35 10 a.m.(COLUMN)57(COLUMN)30 11 a.m.(COLUMN)59(COLUMN)29 12 noon(COLUMN)63(COLUMN)25 1 p.m.(COLUMN)66(COLUMN)23 2 p.m.(COLUMN)69(COLUMN)18 3 p.m.(COLUMN)69(COLUMN)18 4 p.m.(COLUMN)69(COLUMN)17 5 p.m.(COLUMN)68(COLUMN)17 6 p.m.(COLUMN)66(COLUMN)18 7 p.m.(COLUMN)63(COLUMN)19(END TABLE) Temperatures ending 7 a.m. (EST) yesterday:(TABLE) City(COLUMN)H.(COLUMN)L. Albany(COLUMN)73(COLUMN)38 Albuquerque(COLUMN)79(COLUMN)48 Amarillo(COLUMN)78(COLUMN)50 Anchorage(COLUMN)47(COLUMN)35 Asheville(COLUMN)73(COLUMN)43 Atlanta(COLUMN)72(COLUMN)45 Atlanta City(COLUMN)62(COLUMN)46 Austin(COLUMN)77(COLUMN)54 Baltimore(COLUMN)77(COLUMN)45 Billings(COLUMN)54(COLUMN)29 Birmingham(COLUMN)72(COLUMN)39 Bismarck(COLUMN)47(COLUMN)25 Boise(COLUMN)64(COLUMN)36 Boston(COLUMN)75(COLUMN)46 Brownsville(COLUMN)80(COLUMN)57 Buffalo(COLUMN)60(COLUMN)35 Burlington, Vt.(COLUMN)64(COLUMN)36 Casper(COLUMN)52(COLUMN)32 Charleston, S.C.(COLUMN)71(COLUMN)55 Ch'leston, W.V.(COLUMN)68(COLUMN)38 Charlotte(COLUMN)72(COLUMN)42 Cheyenne(COLUMN)53(COLUMN)32 Chicago(COLUMN)54(COLUMN)41 Cincinnati(COLUMN)60(COLUMN)31 Cleveland(COLUMN)60(COLUMN)32 Columbia, S.C.(COLUMN)69(COLUMN)50 Columbus(COLUMN)59(COLUMN)35 Dal.-Ft. Worth(COLUMN)81(COLUMN)53 Dayton(COLUMN)58(COLUMN)34 Denver(COLUMN)59(COLUMN)42 Des Moines(COLUMN)59(COLUMN)42 Detroit(COLUMN)55(COLUMN)30 Duluth(COLUMN)38(COLUMN)30 El Paso(COLUMN)80(COLUMN)51 Fairbanks(COLUMN)49(COLUMN)34 Fargo(COLUMN)42(COLUMN)25 Flagstaff(COLUMN)60(COLUMN)32 Great Falls(COLUMN)54(COLUMN)26 Hartford(COLUMN)80(COLUMN)44 Helena(COLUMN)57(COLUMN)34 Honolulu(COLUMN)83(COLUMN)71 Houston(COLUMN)78(COLUMN)60 Indianapolis(COLUMN)62(COLUMN)39 Jackson(COLUMN)75(COLUMN)44 Jacksonville(COLUMN)80(COLUMN)60 Juneau(COLUMN)55(COLUMN)29 Kansas City(COLUMN)63(COLUMN)49 Las Vegas(COLUMN)83(COLUMN)59 Little Rock(COLUMN)73(COLUMN)48 Los Angeles(COLUMN)67(COLUMN)57 Louisville(COLUMN)65(COLUMN)39 Memphis(COLUMN)71(COLUMN)47 Miami Beach(COLUMN)80(COLUMN)76 Midland(COLUMN)85(COLUMN)56 Milwaukee(COLUMN)52(COLUMN)31 Mpls.-St. Paul(COLUMN)49(COLUMN)29 Nashville(COLUMN)70(COLUMN)42 New Orleans(COLUMN)76(COLUMN)55 New York(COLUMN)76(COLUMN)48 Norfolk(COLUMN)67(COLUMN)53 North Platte(COLUMN)67(COLUMN)44 Oklahoma City(COLUMN)76(COLUMN)56 Omaha(COLUMN)62(COLUMN)43 Orlando(COLUMN)93(COLUMN)70 Philadelphia(COLUMN)75(COLUMN)42 Phoenix(COLUMN)89(COLUMN)70 Pittsburgh(COLUMN)66(COLUMN)34 Portland, Me.(COLUMN)53(COLUMN)36 Portland, Or.(COLUMN)55(COLUMN)44 Providence(COLUMN)67(COLUMN)44 Raleigh(COLUMN)73(COLUMN)43 Raipd City(COLUMN)55(COLUMN)30 Reno(COLUMN)61(COLUMN)31 Richmond(COLUMN)78(COLUMN)48 St. Louis(COLUMN)63(COLUMN)40 St. Pbg.-Tampa(COLUMN)86(COLUMN)67 Salt Lake City(COLUMN)58(COLUMN)47 San Antonio(COLUMN)76(COLUMN)48 San Diego(COLUMN)68(COLUMN)61 San Francisco(COLUMN)59(COLUMN)53 San Juan(COLUMN)84(COLUMN)73 St. Ste. Marie(COLUMN)36(COLUMN)20 Seattle(COLUMN)53(COLUMN)43 Shreveport(COLUMN)80(COLUMN)46 Sioux Falls(COLUMN)56(COLUMN)31 Spokane(COLUMN)55(COLUMN)40 Syracuse(COLUMN)66(COLUMN)35 Topeka(COLUMN)65(COLUMN)48 Tucson(COLUMN)87(COLUMN)60 Tulsa(COLUMN)75(COLUMN)57 Washington(COLUMN)80(COLUMN)47 Wichita(COLUMN)71(COLUMN)54(END TABLE) Temperatures Abroad Yesterday(TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)Temp Aberdeen(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)43 Amsterdam(COLUMN)rain(COLUMN)1 p.m.(COLUMN)41 Ankara(COLUMN)pt. cldy(COLUMN)3 p.m.(COLUMN)68 Athens(COLUMN)cloudy(COLUMN)2 p.m.(COLUMN)63 Auckland(COLUMN)cloudy(COLUMN)midnight(COLUMN)59 Berlin(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)48 Birmingham(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)46 Brussels(COLUMN)rain(COLUMN)1 p.m.(COLUMN)41 Casablanca(COLUMN)clear(COLUMN)noon(COLUMN)63 Copenhagen(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)45 Dublin(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)50 Geneva(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)43 Hong Kong(COLUMN)pt. cldy(COLUMN)8 p.m.(COLUMN)73 London(COLUMN)pt cldy(COLUMN)1 p.m.(COLUMN)45 Madrid(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)63 Malta(COLUMN)clear(COLUMN)1 p.m.(COLUMN)63 Manila(COLUMN)clear(COLUMN)8 p.m.(COLUMN)84 Moscow(COLUMN)cloudy(COLUMN)3 p.m.(COLUMN)50 New Delhi(COLUMN)cloudy(COLUMN)5 p.m.(COLUMN)99 Nice(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)57 Oslo(COLUMN)clear(COLUMN)1 p.m.(COLUMN)46 Paris(COLUMN)rain(COLUMN)1 p.m.(COLUMN)41 Peking(COLUMN)smoke(COLUMN)8 p.m.(COLUMN)57 Rome(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)54 Sofia(COLUMN)pt. cldy(COLUMN)2 p.m.(COLUMN)66 Stockholm(COLUMN)clear(COLUMN)1 p.m.(COLUMN)45 Sydney(COLUMN)rain(COLUMN)10 p.m.(COLUMN)63 Tel Aviv(COLUMN)clear(COLUMN)2 p.m.(COLUMN)90 Tokyo(COLUMN)clear(COLUMN)9 p.m.(COLUMN)57 Tunis(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)64 Vienna(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)46 Warsaw(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)39(END TABLE) Temperatures (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)High(COLUMN)Low Acapulco(COLUMN)clear(COLUMN)88(COLUMN)73 Barbados(COLUMN)fair(COLUMN)84(COLUMN)79 Bermuda(COLUMN)pt. cldy(COLUMN)74(COLUMN)68 Bogota(COLUMN)cloudy(COLUMN)68(COLUMN)50 Calgary(COLUMN)snow(COLUMN)36(COLUMN)23 Cullacan(COLUMN)pt. cldy(COLUMN)88(COLUMN)64 Edmonton(COLUMN)cloudy(COLUMN)41(COLUMN)21 Havana(COLUMN)pt. cldy(COLUMN)90(COLUMN)75 Montego Bay(COLUMN)pt. cldy(COLUMN)86(COLUMN)72 Mexico City(COLUMN)fair(COLUMN)81(COLUMN)52 Monterrey(COLUMN)fair(COLUMN)86(COLUMN)64 Montreal(COLUMN)snow(COLUMN)55(COLUMN)34 Nassau(COLUMN)fair(COLUMN)84(COLUMN)72 Ottawa(COLUMN)cloudy(COLUMN)55(COLUMN)34 Regina(COLUMN)cloudy(COLUMN)43(COLUMN)28 St. Kitts(COLUMN)pt. cldy(COLUMN)86(COLUMN)75 St. Thomas(COLUMN)pt. cldy(COLUMN)85(COLUMN)73 Toronto(COLUMN)clear(COLUMN)50(COLUMN)32 Vancouver(COLUMN)cloudy(COLUMN)52(COLUMN)39 Veracruz(COLUMN)fair(COLUMN)82(COLUMN)68 Winnipeg(COLUMN)clear(COLUMN)37(COLUMN)27(END TABLE)