When it comes to post allowance, the U.S. State Department has been more Grinch than Santa Claus the last three months. Now, with the holiday season in full swing, it’s been both.

On Sunday, the department’s Office of Allowances raised post allowance rates for U.S. civilian employees in some European countries that use the euro, and dropped rates in the United Kingdom for the fourth time in as many months.

The rate changes were in reaction to currency fluctuations, according to a memo posted Saturday on the office’s Web site.

Civilians eligible for post allowance and stationed in Germany, the Netherlands and Portugal will see modest increases in their next paychecks − roughly $50 more for those making between $42,000 and $44,999 per year with two dependents.

Employees making similar pay at most major bases in the U.K. will get about $50 less, while those in other European countries where large numbers of U.S. troops are stationed will not see a change.

It is not unusual for allowance rates in some countries to increase while others decline, but the latest adjustment has, for the first time, left those working in the U.K. with less cash than their counterparts in Portugal, according to records available through the Office of Allowances’ Web site. Post allowance rates in the U.K. are now at their lowest point in more than six years, according to those same records.

It is clear that the British pound’s weakness against the dollar has driven the decline in post allowance in the U.K. In midday trading Friday, a pound cost $1.4606, according to Federal Reserve Bank of New York data. Not since June 7, 2002, when a pound cost $1.4604 according to reserve bank data, has the exchange rate been so favorable to the greenback.

The dollar weakened a little more than a penny against the euro since the last allowance rate adjustment, based on a two-week average.