<TABLE> <S> <C>

<PAGE>
 
<ARTICLE> 9
<MULTIPLIER> 1,000
       
<S>                             <C>                     <C>
<PERIOD-TYPE>                   6-MOS                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1998             DEC-31-1997
<PERIOD-START>                             JAN-01-1998             JAN-01-1997
<PERIOD-END>                               JUN-30-1998             JUN-30-1997
<CASH>                                           6,109                  17,348
<INT-BEARING-DEPOSITS>                             105                     200
<FED-FUNDS-SOLD>                                     0                       0
<TRADING-ASSETS>                                     0                       0
<INVESTMENTS-HELD-FOR-SALE>                    262,751                 111,475
<INVESTMENTS-CARRYING>                               0                       0
<INVESTMENTS-MARKET>                                 0                       0
<LOANS>                                        721,960                 771,612
<ALLOWANCE>                                     (7,937)                 (6,687)
<TOTAL-ASSETS>                               1,013,178                 916,322
<DEPOSITS>                                     737,453                 685,308
<SHORT-TERM>                                    84,800                  78,000
<LIABILITIES-OTHER>                              7,646                  11,594
<LONG-TERM>                                    127,919                  90,388
<PREFERRED-MANDATORY>                                0                       0
<PREFERRED>                                          0                       0
<COMMON>                                         1,377                   1,377
<OTHER-SE>                                      53,983                  49,655
<TOTAL-LIABILITIES-AND-EQUITY>               1,013,178                 916,322
<INTEREST-LOAN>                                 32,913                  33,072
<INTEREST-INVEST>                                7,377                   3,692
<INTEREST-OTHER>                                   245                     198
<INTEREST-TOTAL>                                40,535                  36,962
<INTEREST-DEPOSIT>                              19,164                  18,352
<INTEREST-EXPENSE>                              25,302                  23,112
<INTEREST-INCOME-NET>                           15,233                  13,850
<LOAN-LOSSES>                                    1,524                   1,519
<SECURITIES-GAINS>                               4,767                     589
<EXPENSE-OTHER>                                 23,355                  10,201
<INCOME-PRETAX>                                  5,988                   6,000
<INCOME-PRE-EXTRAORDINARY>                       5,988                   6,000
<EXTRAORDINARY>                                      0                       0
<CHANGES>                                            0                       0
<NET-INCOME>                                     3,515                   3,271
<EPS-PRIMARY>                                     2.55                    2.38
<EPS-DILUTED>                                     2.55                    2.38
<YIELD-ACTUAL>                                    3.22                    3.35
<LOANS-NON>                                      7,253                   5,381
<LOANS-PAST>                                         0                       0
<LOANS-TROUBLED>                                 2,034                   2,072
<LOANS-PROBLEM>                                  9,287                   7,453
<ALLOWANCE-OPEN>                                 7,333                   5,904
<CHARGE-OFFS>                                    1,412                   1,060
<RECOVERIES>                                       492                     324
<ALLOWANCE-CLOSE>                                7,937                   6,687
<ALLOWANCE-DOMESTIC>                             7,937                   6,687
<ALLOWANCE-FOREIGN>                                  0                       0
<ALLOWANCE-UNALLOCATED>                              0                       0
        

                                     


</TABLE>