You mean like this?
I've been using Windy to show wind forecast on my Saratoga Template site for quite some time. I just use the embed code provided by Windy, added it to a new page, and then added that page to the menu system.
<?php
############################################################################
# A Project of TNET Services, Inc. and Saratoga-Weather.org (Canada/World-ML template set)
############################################################################
#
# Project: Sample Included Website Design
# Module: sample.php
# Purpose: Sample Page
# Authors: Kevin W. Reed <kreed@tnet.com>
# TNET Services, Inc.
#
# Copyright: (c) 1992-2007 Copyright TNET Services, Inc.
############################################################################
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
############################################################################
# This document uses Tab 4 Settings
############################################################################
require_once("Settings.php");
require_once("common.php");
############################################################################
$TITLE = langtransstr($SITE['organ']) . " - " .langtransstr('Wind');
$showGizmo = false; // set to false to exclude the gizmo
include("top.php");
############################################################################
?>
</head>
<body>
<?php
############################################################################
include("header.php");
############################################################################
include("menubar.php");
############################################################################
?>
<iframe src="https://embed.windyty.com/?44.675,-76.358,10,menu,marker,metric.wind.km/h" width="670" height="500" frameborder="0"></iframe>
<div id="main-copy">
<><!-- end main-copy -->
<?php
############################################################################
include("footer.php");
############################################################################
# End of Page
############################################################################
?>
Should work the same way for the map you want to display on your site.
Cheers!
Chris