In a year remembered for no landfalling Atlantic hurricanes -- following heavy landfalling hurricane activity in 2004 and 2005 -- global tropical activity was normal, according to a report issued by Impact Forecasting, LLC, a unit of Aon Corporation (NYSE: AOC).

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The combined number of tropical cyclones for the Northern Hemisphere was 31 in 2006, equal to the long-term average. However, more intense tropical cyclones (categories 3, 4 and 5) exceeded historical levels by 45 percent. Less intense tropical cyclones were below the long-term average by 33 percent.

  2006 Tropical Activity vs. Long-Term Averages
   Saffir-                                         East           West
  Simpson      Northern           Atlantic        Pacific        Pacific
   Scale       Hemisphere          Basin           Basin          Basin
           Avg. 2006 Chg.  %  Avg. 2006  Chg. Avg. 2006  Chg. Avg. 2006  Chg.
   1 & 2   17.9  12 -5.9 -33% 5.1    3  -2.1  4.9    5  +0.1  7.9    4  -3.9
  3, 4 & 5 13.1  19 +5.9 +45% 1.1    2  +0.9  2.5    6  +3.5  9.5   11  +1.5
   TOTAL   31.0  31   0   0%  6.2    5  -1.2  7.4   11  +3.6 17.4   15  -2.4

While significant attention has been devoted to the fact that no hurricanes made landfall in the United States in 2006, hurricane activity in the Atlantic Basin lagged historical norms by only 1.2 events. Consistent with expectations for periods with above-average sea surface temperatures, more intense hurricanes (categories 3, 4 and 5) were above average by 0.9 events (81 percent), and less intense hurricanes (categories 1 and 2) were below average by 2.1 events (41 percent). Using historical hurricane landfall data for the United States when higher sea surface temperatures were present, the likelihood that no hurricanes would make landfall (similar to what occurred in 2006) is 25 percent.

Activity in the eastern Pacific Ocean was greater year-over-year, with 18 named storms, up from 15 in 2005. The eastern Pacific experienced six intense hurricanes (categories 3, 4 and 5) in 2006 versus a long-term average of 2.5 per year with Hurricane Ioke reaching Category 5 status in August.

The activity in the western Pacific was down slightly with 15 typhoons versus the long-term average of 17.4. However, the number of intense storms was above average with 11 storms versus a long-term average of 9.5.

"As evidenced by the recent El Nino patterns in the Pacific and resulting effects to the Atlantic basin, continued vigilance is required on a global basis. This study reinforces the need for catastrophe modeling, and the focus needs to remain on the big picture, rather than on activity in a single year or a single region," said Steve Jakubowski, executive vice president and chief operating officer with Aon Re's Impact Forecasting unit.

Aon Re's Annual Global Climate and Catastrophe Report: 2006, which summarizes the world's climate and natural catastrophes in 2006, details the physical and economic effects of -- and losses of life caused by -- significant weather activity around the world. The top catastrophe losses of 2006 are summarized in the table below.

  Top 10 Catastrophe Losses for 2006
  Event Date   Event Type      Region         Location      Damage Estimates
  4/13-4/15  Severe Weather United States Great Lakes, Ohio  $3.4+ billion
                                          Valley, Southeast
   7/9-7/14  Tropical Storm     Asia        Philippines,     $3.3+ billion
                 Bilis                     Taiwan, China
     5/31      Earthquake       Asia      Indonesia - Java   $3.1+ billion
                                               Island
   4/7-4/8   Severe Weather United States    Great Plains,   $2.6+ billion
                                          Midwest, Southeast
   6/1-6/30      Flood          Asia           China         $2.5+ billion
  9/10-9/17     Typhoon         Asia      Southern Japan,    $2.0+ billion
               Shanshan                     South Korea
  3/11-3/12  Severe Weather United States Southern Plains,   $1.8+ billion
                                          Middle MS Valley
   8/5-8/10  Super Typhoon      Asia           China         $1.6+ billion
                Saomai
  8/23-8/24  Severe Weather United States  Northern Great    $1.1+ billion
                                           Plains, Midwest
    12/25      Earthquake       Asia           Taiwan        $1.0+ billion

The full report is available at http://www.aon.com/ and at http://www.impactforecasting.com/ .

  Media contact:
  Rahsaan Johnson
  312.381.2684
  Rahsaan_Johnson@aon.com

  About Aon

Aon Corporation ( http://www.aon.com/ ) is a leading provider of risk management services, insurance and reinsurance brokerage, human capital and management consulting, and specialty insurance underwriting. Aon has 45,000 employees in 500 offices in more than 120 countries. Backed by broad resources, industry knowledge and technical expertise, Aon professionals help a wide range of clients develop effective risk management and workforce productivity solutions.

This press release contains certain statements related to future results, or states our intentions, beliefs and expectations or predictions for the future which are forward-looking statements as that term is defined in the Private Securities Litigation Reform Act of 1995. These forward-looking statements are subject to certain risks and uncertainties that could cause actual results to differ materially from either historical or anticipated results depending on a variety of factors. Potential factors that could impact results include: general economic conditions in different countries in which we do business around the world, changes in global equity and fixed income markets that could affect the return on invested assets, fluctuations in exchange and interest rates that could influence revenue and expense, rating agency actions that could affect our ability to borrow funds, funding of our various pension plans, changes in the competitive environment, our ability to implement restructuring initiatives and other initiatives intended to yield cost savings, our ability to execute the stock repurchase program, our ability to obtain regulatory or legislative changes to permit continuous sales of our supplemental Medicare health product, changes in commercial property and casualty markets and commercial premium rates that could impact revenues, changes in revenues and earnings due to the elimination of contingent commissions, other uncertainties surrounding a new compensation model, the impact of investigations brought by state attorneys general, state insurance regulators, federal prosecutors, and federal regulators, the impact of class actions and individual lawsuits including client class actions, securities class actions, derivative actions, and ERISA class actions, the cost of resolution of other contingent liabilities and loss contingencies, and the difference in ultimate paid claims in our underwriting companies from actuarial estimates. Further information concerning the Company and its business, including factors that potentially could materially affect the Company's financial results, is contained in the Company's filings with the Securities and Exchange Commission.

First Call Analyst:
FCMN Contact: rahsaan.johnson@aon.com

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SOURCE: Aon Corporation

CONTACT: Rahsaan Johnson of Aon Corporation, +1-312-381-2684, or
Rahsaan_Johnson@aon.com

Web site: http://www.aon.com/
http://www.impactforecasting.com/