Washington: Today - Sunny, high in mid 70s, low in mid 50s. Chance of rain is near zero through tonight. Winds will be light and variable. Saturday - Mostly cloudy, high in 70s.

Maryland and Virginia: Today - Sunny, high in low to mid 70s, low in 50s. Saturday - Mostly cloudy, high in 70s to near 80.

Extended Area Outlook for Sunday through Tuesday: Variable cloudiness with a chance of showers on Sunday and Monday with partial clearing on Tuesday. Highs will be in the 70s and lows in the 50s. Normal Washington temperatures for the period will be a high of 75 and a low of 55.

Lower Potomac and Chesapeake Bay: Today - Fair, visibility more than five miles. Winds will be easterly at 12 to 18 knots. Waves in unprotected waters will be two feet.

West Virginia: Today - Sunny, highs in mid 60s to mid 70s, lows in low 40s to low 50s with some 30s in the mountains. Saturday - Partly cloudy, high in mid 70s.

The National Weather Forecast for today - Most of the nation will enjoy a sunny pleasant day. Thundershowers will be scattered along the Gulf Coast, especially through the Mississippi delta. Rain will spread across the northern Mississippi Valley. Even with sunny skies the Great Lakes region and New England will remain rather cool, in the 60s. Hot weather will persist through the deserts of Arizona and southern California. The West Coast will also be hot.

The Council of Government's Air Quality Index for yesterday showed the high reading in the Washington area during the 2 to 3 p.m. period was 28 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 remain near 2.9 feet today.

Almanac Data for today: The sun rises 7:02 a.m., sets 6.54 p.m.; moon rises 4:23 a.m., sets 5:36 p.m. Tides: high 6:44 a.m. and 7:14 p.m., low 1:09 a.m. and 1:35 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).

Pollen Count: 18 Ragweed (a reading of more than 7 is considered to be undesirable).

The Nation Yesterday: Most of the nation from New England, through the Plains, to the southwest had sunny skies.Northern lower Michigan recovered from an early morning frost and was already in the 60s. In fact the northern half of the nation was enjoying pleasant temperatures. Sunshine was not needed everywhere. The West Coast was warming much too rapidly, the inland deserts were already in the 100s at noon local time, Norton AFB at San Bernardino was 103 degrees. Morning cloudiness and light fog held the temperatures down at San Diego and Los Angeles, only in the low 80's. Thundershowers were widely scattered along the Gulf Coast with warm and humid weather continuing. Only light rainfall was measured with the heaviest activity restricted to offshore. Flooding was occuring near Presidio, Tex., along the Mexican border of southwest Texas. Previous heavy rains through this area pushed reservoirs beyond capacity and now water was being released down the Rio Conchos. Waters were rising at an alarming rate and the city of Presidio could be in danger. Local Temps., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 midnte(COLUMN)63(COLUMN)75 1 a.m.(COLUMN)63(COLUMN)75 2 a.m.(COLUMN)61(COLUMN)81 3 a.m.(COLUMN)61(COLUMN)81 4 a.m.(COLUMN)62(COLUMN)78 5 a.m.(COLUMN)62(COLUMN)78 6 a.m.(COLUMN)61(COLUMN)81 7 a.m.(COLUMN)61(COLUMN)84 8 a.m.(COLUMN)62(COLUMN)78 9 a.m.(COLUMN)63(COLUMN)75 10 a.m.(COLUMN)67(COLUMN)68 11 a.m.(COLUMN)74(COLUMN)54 12 noon(COLUMN)76(COLUMN)50 1 p.m.(COLUMN)77(COLUMN)50 2 p.m.(COLUMN)77(COLUMN)45 3 p.m.(COLUMN)77(COLUMN)35 4 p.m.(COLUMN)77(COLUMN)33 5 p.m.(COLUMN)74(COLUMN)32 6 p.m.(COLUMN)74(COLUMN)32 7 p.m.(COLUMN)70(COLUMN)36(END TABLE) Temperatures ending 8 a.m. (EDT) yesterday(TABLE) City(COLUMN)H.(COLUMN)L. Albany(COLUMN)68(COLUMN)51 Albuquerque(COLUMN)82(COLUMN)53 Amarillo(COLUMN)77(COLUMN)56 Anchorage(COLUMN)60(COLUMN)41 Asheville(COLUMN)78(COLUMN)51 Atlanta(COLUMN)78(COLUMN)59 Atlantic City(COLUMN)64(COLUMN)55 Austin(COLUMN)72(COLUMN)65 Baltimore(COLUMN)75(COLUMN)53 Billings(COLUMN)85(COLUMN)57 Birmingham(COLUMN)77(COLUMN)61 Bismarck(COLUMN)65(COLUMN)45 Boise(COLUMN)81(COLUMN)47 Boston(COLUMN)68(COLUMN)53 Brownsville(COLUMN)90(COLUMN)71 Buffalo(COLUMN)62(COLUMN)44 Burlington(COLUMN)67(COLUMN)53 Casper(COLUMN)84(COLUMN)54 Charleston, S.C.(COLUMN)76(COLUMN)62 Charleston, W. Va.(COLUMN)76(COLUMN)61 Charlotte(COLUMN)73(COLUMN)56 Cheyenne(COLUMN)75(COLUMN)49 Chicago(COLUMN)69(COLUMN)47 Cincinnati(COLUMN)82(COLUMN)51 Cleveland(COLUMN)81(COLUMN)53 Columbia, S.C.(COLUMN)80(COLUMN)53 Columbus(COLUMN)80(COLUMN)46 Dal.-Ft. Worth(COLUMN)77(COLUMN)65 Dayton(COLUMN)80(COLUMN)45 Denver(COLUMN)83(COLUMN)54 Des Moines(COLUMN)70(COLUMN)45 Detroit(COLUMN)78(COLUMN)39 Duluth(COLUMN)59(COLUMN)38 El Paso(COLUMN)76(COLUMN)54 Fairbanks(COLUMN)55(COLUMN)47 Fargo(COLUMN)64(COLUMN)45 Flagstaff(COLUMN)79(COLUMN)44 Great Falls(COLUMN)85(COLUMN)41 Hartford(COLUMN)67(COLUMN)40 Helena(COLUMN)81(COLUMN)51 Honolulu(COLUMN)87(COLUMN)72 Houston(COLUMN)83(COLUMN)67 Indianapolis(COLUMN)81(COLUMN)47 Jackson, Miss.(COLUMN)75(COLUMN)68 Jacksonville(COLUMN)79(COLUMN)64 Juneau(COLUMN)58(COLUMN)47 Kansas City(COLUMN)76(COLUMN)49 Las Vegas(COLUMN)101(COLUMN)69 Little Rock(COLUMN)70(COLUMN)62 Los Angeles(COLUMN)98(COLUMN)74 Louisville(COLUMN)83(COLUMN)57 Memphis(COLUMN)81(COLUMN)64 Miami Beach(COLUMN)86(COLUMN)77 Midland-Odessa(COLUMN)62(COLUMN)53 Milwaukee(COLUMN)61(COLUMN)42 Mpls.-St. Paul(COLUMN)64(COLUMN)39 Nashville(COLUMN)82(COLUMN)60 New Orleans(COLUMN)85(COLUMN)73 New York(COLUMN)67(COLUMN)55 Norfolk(COLUMN)72(COLUMN)55 North Platte(COLUMN)79(COLUMN)50 Oklahoma City(COLUMN)84(COLUMN)63 Omaha(COLUMN)70(COLUMN)49 Orlando(COLUMN)89(COLUMN)71 Philadelphia(COLUMN)71(COLUMN)55 Phoenix(COLUMN)101(COLUMN)76 Pittsburgh(COLUMN)74(COLUMN)47 Portland, Me.(COLUMN)63(COLUMN)48 Portland, Ore.(COLUMN)70(COLUMN)56 Providence(COLUMN)63(COLUMN)47 Raleigh(COLUMN)77(COLUMN)51 Rapid City(COLUMN)89(COLUMN)56 Reno(COLUMN)87(COLUMN)37 Richmond(COLUMN)77(COLUMN)55 St. Louis(COLUMN)85(COLUMN)48 St. Prbg.-Tampa(COLUMN)88(COLUMN)72 Salt Lake City(COLUMN)86(COLUMN)56 San Antonio(COLUMN)72(COLUMN)65 San Diego(COLUMN)84(COLUMN)71 San Francisco(COLUMN)67(COLUMN)57 San Juan(COLUMN)93(COLUMN)78 St. Ste. Marie(COLUMN)57(COLUMN)36 Seattle(COLUMN)70(COLUMN)54 Shreveport(COLUMN)78(COLUMN)67 Sioux Falls(COLUMN)67(COLUMN)48 Spokane(COLUMN)70(COLUMN)45 Syracuse(COLUMN)74(COLUMN)48 Topeka(COLUMN)78(COLUMN)42 Tucson(COLUMN)92(COLUMN)73 Tulsa(COLUMN)89(COLUMN)57 Washington(COLUMN)75(COLUMN)60 Wichita(COLUMN)84(COLUMN)55(END TABLE) Temperatures (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)High(COLUMN)Low Acapulco(COLUMN)pt. cldy(COLUMN)88(COLUMN)77 Barbados(COLUMN)pt. cldy(COLUMN)88(COLUMN)77 Bogota(COLUMN)cloudy(COLUMN)64(COLUMN)44 Calgary(COLUMN)clear(COLUMN)55(COLUMN)41 Culiacan(COLUMN)pt. cldy(COLUMN)79(COLUMN)74 Edmonton(COLUMN)fog(COLUMN)59(COLUMN)39 Havana(COLUMN)pt. cldy(COLUMN)86(COLUMN)75 Kingston(COLUMN)pt. cldy(COLUMN)90(COLUMN)79 Montego Bay(COLUMN)pt. cldy(COLUMN)86(COLUMN)76 Mexico City(COLUMN)pt. cldy(COLUMN)79(COLUMN)58 Monterrey(COLUMN)pt. cldy(COLUMN)73(COLUMN)65 Montreal(COLUMN)cloudy(COLUMN)72(COLUMN)46 Nassau(COLUMN)pt. cldy(COLUMN)88(COLUMN)45 Ottawa(COLUMN)cloudy(COLUMN)68(COLUMN)43 Regina(COLUMN)pt. cldy(COLUMN)66(COLUMN)41 Toronto(COLUMN)clear(COLUMN)73(COLUMN)37 Vancouver(COLUMN)rain(COLUMN)66(COLUMN)55 Vera Cruz(COLUMN)pt. cldy(COLUMN)90(COLUMN)74 Winnipeg(COLUMN)cloudy(COLUMN)63(COLUMN)39(END TABLE)