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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K/A

(Amendment No. 1)

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): December 27, 2013

Terreno Realty Corporation

(Exact name of registrant as specified in its charter)

101 Montgomery Street, Suite 200

San Francisco, CA 94104

(Address of principal executive offices) (Zip Code)

(415) 655-4580

(Registrant’s telephone number, including area code)

Check the appropriate box below if the Form 8-K/A filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

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This Form 8-K/A amends and supplements the registrant’s Form 8-K, filed on December 31, 2013 reporting the acquisition of JFK Airgate (the “Initial Report”), to include the historical financial statements and pro forma financial information required by Item 9.01(a) and (b) of Form 8-K. This Form 8-K/A should be read in conjunction with the Initial Report.

Item 9.01. Financial Statements and Exhibits

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Report of Independent Auditors

The Board of Directors and Stockholders of

Terreno Realty Corporation

We have audited the accompanying statement of revenues and certain expenses of JFK Airgate (the “Property”), for the year ended December 31, 2012, and the related notes to the financial statements.

Management’s Responsibility for the Financial Statements

Management is responsible for the preparation and fair presentation of the statement of revenues and certain expenses in conformity with U.S. generally accepted accounting principles; this includes the design, implementation, and maintenance of internal control relevant to the preparation and fair presentation of the statement of revenues and certain expenses that are free of material misstatement, whether due to fraud or error.

Auditor’s Responsibility

Our responsibility is to express an opinion on the statement of revenues and certain expenses based on our audit. We conducted our audit in accordance with auditing standards generally accepted in the United States. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the statement of revenues and certain expenses is free of material misstatement.

An audit involves performing procedures to obtain audit evidence about the amounts and disclosures in the statement of revenues and certain expenses. The procedures selected depend on the auditor’s judgment, including the assessment of the risks of material misstatement of the statement of revenues and certain expenses, whether due to fraud or error. In making those risk assessments, the auditor considers internal control relevant to the entity’s preparation and fair presentation of the statement of revenues and certain expenses in order to design audit procedures that are appropriate in the circumstances, but not for the purpose of expressing an opinion on the effectiveness of the entity’s internal control. Accordingly, we express no such opinion. An audit also includes evaluating the appropriateness of accounting policies used and the reasonableness of significant accounting estimates made by management, as well as evaluating the overall presentation of the statement of revenues and certain expenses.

We believe that the audit evidence we have obtained is sufficient and appropriate to provide a basis for our audit opinion.

Opinion

In our opinion, the statement of revenues and certain expenses referred to above presents fairly, in all material respects, the revenues and certain expenses described in Note 1 of JFK Airgate for the year ended December 31, 2012, in conformity with U.S. generally accepted accounting principles.

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Basis of Accounting

As described in Note 1 to the financial statements, the statement of revenues and certain expenses of the Property have been prepared for the purpose of complying with the rules and regulations of the Securities and Exchange Commission for inclusion in the Form 8-K/A of Terreno Realty Corporation, and is not intended to be a complete presentation of the Property’s revenues and expenses. Our opinion is not modified with respect to this matter.

/s/ Ernst & Young LLP

San Francisco, California

February 18, 2014

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JFK Airgate

Statements of Revenues and Certain Expenses

For the Nine Months Ended September 30, 2013 (unaudited)

and the Year Ended December 31, 2012

(in thousands)

See accompanying notes to statements of revenues and certain expenses.

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JFK Airgate

Notes to Statements of Revenues and Certain Expenses

For the Nine Months Ended September 30, 2013 (unaudited)

and the Year Ended December 31, 2012

The accompanying statements of revenues and certain expenses present the results of operations of JFK Airgate (the “Property”) for the nine months ended September 30, 2013 (unaudited) and the year ended December 31, 2012. The Property was acquired by a wholly-owned subsidiary of Terreno Realty Corporation from a third-party seller, Prologis Targeted U.S. Logistics Fund, L.P., on December 27, 2013 for approximately $53.1 million. The Property is located in Queens, New York and consists of four multi-tenant industrial buildings containing 229,258 square feet (unaudited), which were approximately 99% leased to 19 tenants (unaudited) at the time of acquisition.

The accompanying statements of revenues and certain expenses have been prepared on the accrual basis of accounting. The statements of revenues and certain expenses have been prepared for the purpose of complying with the provisions of Article 3-14 of Regulation S-X promulgated by the Securities and Exchange Commission and for inclusion in this Current Report on Form 8-K/A of Terreno Realty Corporation and are not intended to be a complete presentation of the revenues and expenses of the Property for the nine months ended September 30, 2013 and the year ended December 31, 2012 as certain expenses, primarily depreciation and amortization expense and other costs not comparable to the proposed future operations of the Property have been excluded. Management is not aware of any material factors at the Property other than those disclosed above, that would cause the reported financial information not to be necessarily indicative of future operating results.

Revenue Recognition

Rental revenues from operating leases are recorded on a straight-line basis over the terms of the leases. Tenant reimbursements represent recoveries from tenants for utilities and certain property maintenance expenses. Tenant reimbursements are recognized as revenues in the period the applicable costs are accrued.

Property Operating Expenses

Property operating expenses represent the direct expenses of operating the Property and include maintenance, utilities, property management fees, repairs, and insurance costs that are expected to continue in the ongoing operations of the Property. Expenditures for maintenance and repairs are charged to operations as incurred.

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Use of Estimates

The preparation of the statements of revenues and certain expenses in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions of the reported amounts of revenues and certain expenses during the reporting period. Actual results could differ from those estimates used in the preparation of the statements of revenues and certain expenses.

Interim Statements

The statement of revenues and certain expenses for the nine months ended September 30, 2013 is unaudited, however, in the opinion of management of Terreno Realty Corporation, all significant adjustments necessary for a fair presentation of the statement for the interim period have been included. The results of operations for the interim period are not necessarily indicative of the results to be expected for the full year of the operation of the Property.

Tenant Concentration

For the year ended December 31, 2012, three tenants accounted for approximately 54% of revenues.

Future Minimum Rental Income

Future minimum rents to be received under non-cancelable lease agreements as of December 31, 2012 were as follows (in thousands):

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UNAUDITED PRO FORMA FINANCIAL INFORMATION OF TERRENO REALTY CORPORATION

The following unaudited pro forma financial information of Terreno Realty Corporation (the “Company”) is based on the historical financial statements of the Company. The unaudited pro forma condensed consolidated balance sheet as of September 30, 2013 is based on the Company’s consolidated balance sheet and reflects the subsequent acquisitions of Michele, Meadow, Ethel, 8215 Dorsey, Forbes, Broadway, Pennsy and JFK Airgate and the related borrowings on the term loan payable and revolving credit facility as if such transactions had occurred on September 30, 2013. The unaudited pro forma condensed consolidated statements of operations and comprehensive income for the nine months ended September 30, 2013 and the year ended December 31, 2012 have been prepared to reflect the incremental effect of the acquisition of properties by the Company during the period from January 1, 2013 to December 27, 2013 (the “2013 Acquisitions”) and the year ended December 31, 2012 (the “2012 Acquisitions”) as if such transactions had occurred on January 1, 2013 for the September 30, 2013 statements and January 1, 2012 for the December 31, 2012 statement.

The following table summarizes the 2013 and 2012 Acquisitions (in thousands):

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The unaudited pro forma financial information is not necessarily indicative of what the Company’s results of operations or financial condition would have been assuming the acquisition of properties had occurred at the beginning of the periods presented, nor is it indicative of the Company’s results of operations or financial condition for future periods. In management’s opinion, all adjustments necessary to reflect the effects of these transactions have been made. The unaudited pro forma financial information and accompanying notes should be read in conjunction with the Company’s financial statements included on Form 10-K for the year ended December 31, 2012 and Quarterly Report on Form 10-Q for the nine months ended September 30, 2013.

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Terreno Realty Corporation

Pro Forma Condensed Consolidated Balance Sheet

As of September 30, 2013

(in thousands – except share and per share data)

(Unaudited)

See accompanying notes to unaudited pro forma condensed consolidated balance sheet.

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Terreno Realty Corporation

Notes to Pro Forma Condensed Consolidated Balance Sheet

As of September 30, 2013

(Unaudited)

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Terreno Realty Corporation

Pro Forma Condensed Consolidated Statement of Operations

and Comprehensive Income

For the Nine Months Ended September 30, 2013

(in thousands – except share and per share data)

(Unaudited)

See accompanying notes to unaudited pro forma condensed consolidated statement of operations and comprehensive income.

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Terreno Realty Corporation

Notes to Pro Forma Condensed Consolidated Statement of Operations

and Comprehensive Income

For the Nine Months Ended September 30, 2013

(Unaudited)

Rental revenues set forth above include adjustments for straight-line rents and amortization of lease intangibles.

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Terreno Realty Corporation

Pro Forma Condensed Consolidated Statement of Operations

and Comprehensive Income

For the Year Ended December 31, 2012

(in thousands – except share and per share data)

(Unaudited)

See accompanying notes to unaudited pro forma condensed consolidated statement of operations and comprehensive income.

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Terreno Realty Corporation

Notes to Pro Forma Condensed Consolidated Statement of Operations

and Comprehensive Income

For the Year Ended December 31, 2012

(Unaudited)

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Global Plaza, Whittier and 631 Brennan were acquired from unrelated third-parties after a sale/leaseback transaction and did not have historical revenues and expenses as the properties were accepted, owned and operated by the tenants. As such, no property operations have been reflected in the accompanying unaudited pro forma condensed consolidated statement of operations and comprehensive income.

Rental revenues set forth above include adjustments for straight-line rents and amortization of lease intangibles.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

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Exhibit Index

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