<TABLE> <S> <C>
<PAGE>
<ARTICLE> 9
<LEGEND>
THIS SCHEDULE CONTAINS FINANCIAL INFORMATION EXTRACTED FROM THE CONSOLIDATED
FINANCIAL STATEMENTS OF INTERWEST BANCORP, INC. AND FOR THE SIX MONTHS ENDED
JUNE 30, 2000, AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL
STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> DEC-31-2000
<PERIOD-START> JAN-01-2000
<PERIOD-END> JUN-30-2000
<CASH> 76,936
<INT-BEARING-DEPOSITS> 30,111
<FED-FUNDS-SOLD> 15,500
<TRADING-ASSETS> 0
<INVESTMENTS-HELD-FOR-SALE> 690,312
<INVESTMENTS-CARRYING> 67,106
<INVESTMENTS-MARKET> 64,695
<LOANS> 1,741,703
<ALLOWANCE> 15,538
<TOTAL-ASSETS> 2,793,359
<DEPOSITS> 1,583,948
<SHORT-TERM> 594,328
<LIABILITIES-OTHER> 28,755
<LONG-TERM> 425,812
0
0
<COMMON> 25,802
<OTHER-SE> 134,714
<TOTAL-LIABILITIES-AND-EQUITY> 2,793,359
<INTEREST-LOAN> 78,603
<INTEREST-INVEST> 27,998
<INTEREST-OTHER> 880
<INTEREST-TOTAL> 107,481
<INTEREST-DEPOSIT> 28,895
<INTEREST-EXPENSE> 61,242
<INTEREST-INCOME-NET> 46,239
<LOAN-LOSSES> 1,950
<SECURITIES-GAINS> (6,775)
<EXPENSE-OTHER> 45,966
<INCOME-PRETAX> 337
<INCOME-PRE-EXTRAORDINARY> (252)
<EXTRAORDINARY> 0
<CHANGES> 0
<NET-INCOME> (252)
<EPS-BASIC> (0.02)
<EPS-DILUTED> (0.02)
<YIELD-ACTUAL> 3.54
<LOANS-NON> 11,429
<LOANS-PAST> 0
<LOANS-TROUBLED> 0
<LOANS-PROBLEM> 0
<ALLOWANCE-OPEN> 15,182
<CHARGE-OFFS> 1,773
<RECOVERIES> 179
<ALLOWANCE-CLOSE> 15,538
<ALLOWANCE-DOMESTIC> 11,634
<ALLOWANCE-FOREIGN> 0
<ALLOWANCE-UNALLOCATED> 3,904
</TABLE>